Using a zip level to create a floor contour map

Using a zip level to create a floor contour map

Evaluation of Existing Foundation Conditions

Preparing the site for measurement is a crucial step when using a zip level to create a floor contour map. This process ensures that the data collected is accurate and reliable, which is essential for creating a precise map. Here's a detailed guide on how to prepare the site effectively.


First, clear the area of any obstacles. This includes removing furniture, rugs, and any other items that might obstruct the zip level or interfere with the measurement process. A clean, unobstructed space allows for smoother and more accurate measurements.


Next, ensure the floor is level and stable. Uneven surfaces can lead to inaccurate readings, so it's important to check for any dips or bumps. If necessary, use shims or other leveling tools to create a consistent surface. This step is vital for the zip level to function correctly and provide reliable data.


Mark the boundaries of the area you intend to map. Use tape or chalk to outline the space clearly. This helps in keeping the measurements within the desired area and avoids any confusion during the data collection process.


Set up a grid system if the area is large. Divide the space into smaller, manageable sections using string or tape measures. Crack mapping helps track progression over time slab lifting and leveling pier and beam foundation.. This makes it easier to navigate and ensures that you cover the entire area systematically. Each section can be measured individually, which simplifies the process and reduces the chance of errors.


Calibrate the zip level before starting the measurements. Follow the manufacturer's instructions to ensure it is set up correctly. Calibration might involve adjusting the device to account for any elevation changes or environmental factors that could affect the readings.


Finally, take your time and be methodical. Rushing through the process can lead to mistakes. Move slowly and deliberately, ensuring that each measurement is taken accurately. Record the data immediately to avoid any confusion later on.


By following these steps, you'll be well-prepared to use a zip level to create a detailed and accurate floor contour map. This preparation not only enhances the quality of the data but also makes the entire process more efficient and effective.

Setting up zip level equipment to create a floor contour map is a meticulous process that requires precision and attention to detail. The zip level, a versatile tool used in construction and surveying, allows professionals to establish accurate horizontal planes and measure elevation differences. To begin, ensure you have all the necessary components: the zip level itself, a tripod, a measuring tape, a notebook for recording data, and a pencil.


First, select a stable and level surface to place the tripod. This is crucial as any instability will affect the accuracy of your measurements. Once the tripod is securely set up, mount the zip level onto it, ensuring it is perfectly horizontal. This can be achieved by adjusting the tripod legs and using the built-in bubble level on the zip level to confirm its alignment.


Next, use the measuring tape to determine the area you wish to map. Mark the boundaries with chalk or tape to create a clear working area. Begin at one corner of the designated area and place the zip level on the floor. Slowly move the zip level across the surface, taking regular measurements at consistent intervals. Record each measurement in your notebook, noting the exact location and elevation.


As you progress, pay close attention to any irregularities or changes in elevation. These will be critical in creating an accurate contour map. If you encounter obstacles such as furniture or fixtures, take additional measurements around them to ensure you capture the entire floors topography.


Once you have collected all the necessary data, transfer your measurements to a grid on graph paper or use specialized software to plot the points. Connect the points with smooth lines to form contours, which represent areas of equal elevation. This visual representation will help you understand the floors slope and any potential issues that need addressing.


In conclusion, setting up zip level equipment to create a floor contour map is a systematic process that demands careful planning and precise execution. By following these steps, you can achieve an accurate and detailed map that will serve as a valuable tool for any construction or renovation project.

Design Calculations and Load Analysis

Creating a floor contour map using a zip level involves a meticulous process of collecting elevation data points. This task is essential for various applications, including urban planning, flood risk assessment, and architectural design. The first step in this process is to define the geographic area of interest, typically delineated by zip code boundaries. This ensures that the data collected is relevant and localized.


The collection of elevation data points is a critical phase. It requires the use of advanced technologies such as LiDAR (Light Detection and Ranging), which employs laser pulses to measure distances to the Earths surface. This method provides highly accurate and detailed elevation data. Alternatively, traditional surveying methods, involving theodolites and levels, can be used, though they are more time-consuming and labor-intensive.


Once the data is collected, it undergoes a process of cleaning and normalization. This step is vital to ensure the accuracy and reliability of the data. Any outliers or errors in the data are identified and corrected. The normalized data is then input into Geographic Information System (GIS) software. This software is adept at handling spatial data and is crucial for the creation of contour maps.


In the GIS environment, the elevation data points are used to generate a Digital Elevation Model (DEM). This model represents the three-dimensional surface of the ground. From the DEM, contour lines are extracted. These lines connect points of equal elevation and are essential for visualizing the terrains slope and features.


The final step involves the creation of the floor contour map. This map is a two-dimensional representation of the three-dimensional terrain, with contour lines indicating changes in elevation. It is an invaluable tool for various professionals, providing insights into the landscapes topography and aiding in decision-making processes.


In conclusion, the process of collecting elevation data points for creating a floor contour map using a zip level is a complex but rewarding endeavor. It combines advanced technology with traditional surveying methods, and requires careful data processing and analysis. The resulting contour map is a powerful tool for understanding and visualizing the terrain within a specific zip code area.

Design Calculations and Load Analysis

Implementation Plan and Quality Control Measures

When it comes to analyzing and interpreting contour map data at the zip level, there are several key factors to consider. First and foremost, its important to understand what a contour map is and how it works. Essentially, a contour map is a type of map that uses lines to represent changes in elevation or other types of data across a given area. In the case of a floor contour map, these lines would represent changes in the height of the floor across different parts of a building or other structure.


To create a floor contour map at the zip level, you would need to gather data on the elevation of the floor in each zip code within a given area. This data could come from a variety of sources, such as building plans, architectural drawings, or even on-site measurements. Once you have this data, you can use it to create a contour map that shows the changes in floor elevation across the entire area.


Analyzing and interpreting this data can be a complex process, but there are several key steps you can take to make it easier. First, its important to identify any patterns or trends in the data. For example, you might notice that certain zip codes have consistently higher or lower floor elevations than others. This could be due to a variety of factors, such as differences in building design, construction materials, or even local geography.


Once you have identified these patterns, you can begin to look for explanations or causes. This might involve consulting with architects, engineers, or other experts who can help you understand the underlying factors that are driving these trends. It might also involve conducting additional research or analysis to gather more data and test your hypotheses.


Ultimately, the goal of analyzing and interpreting contour map data at the zip level is to gain a deeper understanding of the factors that are shaping the built environment in a given area. By identifying patterns and trends in the data, and by exploring the underlying causes of these patterns, you can gain valuable insights into the ways that buildings, neighborhoods, and cities are designed and constructed. Whether you are a developer, an architect, a city planner, or simply a curious member of the public, this type of analysis can help you make more informed decisions and create more effective, sustainable, and livable communities.

 

Earthquake epicenters occur mostly along tectonic plate boundaries, especially on the Pacific Ring of Fire.

An earthquake, also called a quake, tremor, or temblor, is the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume.

In its most general sense, the word earthquake is used to describe any seismic event that generates seismic waves. Earthquakes can occur naturally or be induced by human activities, such as mining, fracking, and nuclear weapons testing. The initial point of rupture is called the hypocenter or focus, while the ground level directly above it is the epicenter. Earthquakes are primarily caused by geological faults, but also by volcanism, landslides, and other seismic events.

Significant historical earthquakes include the 1556 Shaanxi earthquake in China, with over 830,000 fatalities, and the 1960 Valdivia earthquake in Chile, the largest ever recorded at 9.5 magnitude. Earthquakes result in various effects, such as ground shaking and soil liquefaction, leading to significant damage and loss of life. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can trigger landslides. Earthquakes' occurrence is influenced by tectonic movements along faults, including normal, reverse (thrust), and strike-slip faults, with energy release and rupture dynamics governed by the elastic-rebound theory.

Efforts to manage earthquake risks involve prediction, forecasting, and preparedness, including seismic retrofitting and earthquake engineering to design structures that withstand shaking. The cultural impact of earthquakes spans myths, religious beliefs, and modern media, reflecting their profound influence on human societies. Similar seismic phenomena, known as marsquakes and moonquakes, have been observed on other celestial bodies, indicating the universality of such events beyond Earth.

Terminology

[edit]

An earthquake is the shaking of the surface of Earth resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes may also be referred to as quakes, tremors, or temblors. The word tremor is also used for non-earthquake seismic rumbling.

In its most general sense, an earthquake is any seismic event—whether natural or caused by humans—that generates seismic waves. Earthquakes are caused mostly by the rupture of geological faults but also by other events such as volcanic activity, landslides, mine blasts, fracking and nuclear tests. An earthquake's point of initial rupture is called its hypocenter or focus. The epicenter is the point at ground level directly above the hypocenter.

The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume.

Major examples

[edit]
Earthquakes (M6.0+) since 1900 through 2017
Earthquakes of magnitude 8.0 and greater from 1900 to 2018. The apparent 3D volumes of the bubbles are linearly proportional to their respective fatalities.[1]

One of the most devastating earthquakes in recorded history was the 1556 Shaanxi earthquake, which occurred on 23 January 1556 in Shaanxi, China. More than 100,000 people died, with the region losing up to 830,000 people afterwards due to emmigration, plague, and famine.[2] Most houses in the area were yaodongs—dwellings carved out of loess hillsides—and many victims were killed when these structures collapsed. The 1976 Tangshan earthquake, which killed between 240,000 and 655,000 people, was the deadliest of the 20th century.[3]

The 1960 Chilean earthquake is the largest earthquake that has been measured on a seismograph, reaching 9.5 magnitude on 22 May 1960.[4][5] Its epicenter was near Cañete, Chile. The energy released was approximately twice that of the next most powerful earthquake, the Good Friday earthquake (27 March 1964), which was centered in Prince William Sound, Alaska.[6][7] The ten largest recorded earthquakes have all been megathrust earthquakes; however, of these ten, only the 2004 Indian Ocean earthquake is simultaneously one of the deadliest earthquakes in history.

Earthquakes that caused the greatest loss of life, while powerful, were deadly because of their proximity to either heavily populated areas or the ocean, where earthquakes often create tsunamis that can devastate communities thousands of kilometers away. Regions most at risk for great loss of life include those where earthquakes are relatively rare but powerful, and poor regions with lax, unenforced, or nonexistent seismic building codes.

Occurrence

[edit]
Three types of faults:
A. Strike-slip
B. Normal
C. Reverse

Tectonic earthquakes occur anywhere on the earth where there is sufficient stored elastic strain energy to drive fracture propagation along a fault plane. The sides of a fault move past each other smoothly and aseismically only if there are no irregularities or asperities along the fault surface that increases the frictional resistance. Most fault surfaces do have such asperities, which leads to a form of stick-slip behavior. Once the fault has locked, continued relative motion between the plates leads to increasing stress and, therefore, stored strain energy in the volume around the fault surface. This continues until the stress has risen sufficiently to break through the asperity, suddenly allowing sliding over the locked portion of the fault, releasing the stored energy.[8] This energy is released as a combination of radiated elastic strain seismic waves,[9] frictional heating of the fault surface, and cracking of the rock, thus causing an earthquake.

This process of gradual build-up of strain and stress punctuated by occasional sudden earthquake failure is referred to as the elastic-rebound theory. It is estimated that only 10 percent or less of an earthquake's total energy is radiated as seismic energy. Most of the earthquake's energy is used to power the earthquake fracture growth or is converted into heat generated by friction. Therefore, earthquakes lower the Earth's available elastic potential energy and raise its temperature, though these changes are negligible compared to the conductive and convective flow of heat out from the Earth's deep interior.[10]

Fault types

[edit]

There are three main types of fault, all of which may cause an interplate earthquake: normal, reverse (thrust), and strike-slip. Normal and reverse faulting are examples of dip-slip, where the displacement along the fault is in the direction of dip and where movement on them involves a vertical component. Many earthquakes are caused by movement on faults that have components of both dip-slip and strike-slip; this is known as oblique slip.

The topmost, brittle part of the Earth's crust, and the cool slabs of the tectonic plates that are descending into the hot mantle, are the only parts of our planet that can store elastic energy and release it in fault ruptures. Rocks hotter than about 300 °C (572 °F) flow in response to stress; they do not rupture in earthquakes.[11][12] The maximum observed lengths of ruptures and mapped faults (which may break in a single rupture) are approximately 1,000 km (620 mi). Examples are the earthquakes in Alaska (1957), Chile (1960), and Sumatra (2004), all in subduction zones. The longest earthquake ruptures on strike-slip faults, like the San Andreas Fault (1857, 1906), the North Anatolian Fault in Turkey (1939), and the Denali Fault in Alaska (2002), are about half to one third as long as the lengths along subducting plate margins, and those along normal faults are even shorter.

Normal faults

[edit]

Normal faults occur mainly in areas where the crust is being extended such as a divergent boundary. Earthquakes associated with normal faults are generally less than magnitude 7. Maximum magnitudes along many normal faults are even more limited because many of them are located along spreading centers, as in Iceland, where the thickness of the brittle layer is only about six kilometres (3.7 mi).[13][14]

Reverse faults

[edit]

Reverse faults occur in areas where the crust is being shortened such as at a convergent boundary. Reverse faults, particularly those along convergent boundaries, are associated with the most powerful earthquakes (called megathrust earthquakes) including almost all of those of magnitude 8 or more. Megathrust earthquakes are responsible for about 90% of the total seismic moment released worldwide.[15]

Strike-slip faults

[edit]

Strike-slip faults are steep structures where the two sides of the fault slip horizontally past each other; transform boundaries are a particular type of strike-slip fault. Strike-slip faults, particularly continental transforms, can produce major earthquakes up to about magnitude 8. Strike-slip faults tend to be oriented near vertically, resulting in an approximate width of 10 km (6.2 mi) within the brittle crust.[16] Thus, earthquakes with magnitudes much larger than 8 are not possible.

Aerial photo of the San Andreas Fault in the Carrizo Plain, northwest of Los Angeles

In addition, there exists a hierarchy of stress levels in the three fault types. Thrust faults are generated by the highest, strike-slip by intermediate, and normal faults by the lowest stress levels.[17] This can easily be understood by considering the direction of the greatest principal stress, the direction of the force that "pushes" the rock mass during the faulting. In the case of normal faults, the rock mass is pushed down in a vertical direction, thus the pushing force (greatest principal stress) equals the weight of the rock mass itself. In the case of thrusting, the rock mass "escapes" in the direction of the least principal stress, namely upward, lifting the rock mass, and thus, the overburden equals the least principal stress. Strike-slip faulting is intermediate between the other two types described above. This difference in stress regime in the three faulting environments can contribute to differences in stress drop during faulting, which contributes to differences in the radiated energy, regardless of fault dimensions.

Energy released

[edit]

For every unit increase in seismic magnitude, there is a roughly thirty-fold increase in the energy released. For instance, an earthquake of magnitude 6.0 releases approximately 32 times as much energy as an earthquake of magnitude 5.0, and a 7.0 magnitude earthquake releases about 1,000 times as much energy as a 5.0 magnitude earthquake. An 8.6-magnitude earthquake releases the same amount of energy as 10,000 atomic bombs of the size used in World War II.[18]

This is so because the energy released in an earthquake, and thus its magnitude, is proportional to the area of the fault that ruptures[19] and the stress drop. Therefore, the greater the length and width of the faulted area, the greater the resulting magnitude. The most important parameter controlling the maximum earthquake magnitude on a fault, however, is not the maximum available length, but the available width because the latter varies by a factor of 20. Along converging plate margins, the dip angle of the rupture plane is very shallow, typically about 10 degrees.[20] Thus, the width of the plane within the top brittle crust of the Earth can reach 50–100 km (31–62 mi) (such as in Japan, 2011, or in Alaska, 1964), making the most powerful earthquakes possible.

Focus

[edit]
Collapsed Gran Hotel building in the San Salvador metropolis, after the shallow 1986 San Salvador earthquake

The majority of tectonic earthquakes originate in the Ring of Fire at depths not exceeding tens of kilometers. Earthquakes occurring at depths less than 70 km (43 mi) are classified as "shallow-focus" earthquakes, while those with focal depths between 70 and 300 km (43 and 186 mi) are commonly termed "mid-focus" or "intermediate-depth" earthquakes.

In subduction zones, where older and colder oceanic crust descends beneath another tectonic plate, deep-focus earthquakes may occur at much greater depths (ranging from 300 to 700 km (190 to 430 mi)).[21] These seismically active areas of subduction are known as Wadati–Benioff zones. Deep-focus earthquakes occur at depths where the subducted lithosphere should no longer be brittle, due to the high temperature and pressure. A possible mechanism for the generation of deep-focus earthquakes is faulting caused by olivine undergoing a phase transition into a spinel structure.[22]

Volcanic activity

[edit]

Earthquakes often occur in volcanic regions and are caused there, both by tectonic faults and the movement of magma in volcanoes. Such earthquakes can serve as an early warning of volcanic eruptions, as during the 1980 eruption of Mount St. Helens.[23] Earthquake swarms can serve as markers for the location of the flowing magma throughout the volcanoes. These swarms can be recorded by seismometers and tiltmeters (a device that measures ground slope) and used as sensors to predict imminent or upcoming eruptions.[24]

Rupture dynamics

[edit]

A tectonic earthquake begins as an area of initial slip on the fault surface that forms the focus. Once the rupture has been initiated, it begins to propagate away from the focus, spreading out along the fault surface. Lateral propagation will continue until either the rupture reaches a barrier, such as the end of a fault segment, or a region on the fault where there is insufficient stress to allow continued rupture. For larger earthquakes, the depth extent of rupture will be constrained downwards by the brittle-ductile transition zone and upwards by the ground surface. The mechanics of this process are poorly understood because it is difficult either to recreate such rapid movements in a laboratory or to record seismic waves close to a nucleation zone due to strong ground motion.[25]

In most cases, the rupture speed approaches, but does not exceed, the shear wave (S wave) velocity of the surrounding rock. There are a few exceptions to this:

Supershear earthquakes

[edit]
The 2023 Turkey–Syria earthquakes ruptured along segments of the East Anatolian Fault at supershear speeds; more than 50,000 people died in both countries.[26]

Supershear earthquake ruptures are known to have propagated at speeds greater than the S wave velocity. These have so far all been observed during large strike-slip events. The unusually wide zone of damage caused by the 2001 Kunlun earthquake has been attributed to the effects of the sonic boom developed in such earthquakes.

Slow earthquakes

[edit]

Slow earthquake ruptures travel at unusually low velocities. A particularly dangerous form of slow earthquake is the tsunami earthquake, observed where the relatively low felt intensities, caused by the slow propagation speed of some great earthquakes, fail to alert the population of the neighboring coast, as in the 1896 Sanriku earthquake.[25]

Co-seismic overpressuring and effect of pore pressure

[edit]

During an earthquake, high temperatures can develop at the fault plane, increasing pore pressure and consequently vaporization of the groundwater already contained within the rock.[27][28][29] In the coseismic phase, such an increase can significantly affect slip evolution and speed, in the post-seismic phase it can control the Aftershock sequence because, after the main event, pore pressure increase slowly propagates into the surrounding fracture network.[30][29] From the point of view of the Mohr-Coulomb strength theory, an increase in fluid pressure reduces the normal stress acting on the fault plane that holds it in place, and fluids can exert a lubricating effect. As thermal overpressurization may provide positive feedback between slip and strength fall at the fault plane, a common opinion is that it may enhance the faulting process instability. After the mainshock, the pressure gradient between the fault plane and the neighboring rock causes a fluid flow that increases pore pressure in the surrounding fracture networks; such an increase may trigger new faulting processes by reactivating adjacent faults, giving rise to aftershocks.[30][29] Analogously, artificial pore pressure increase, by fluid injection in Earth's crust, may induce seismicity.

Tidal forces

[edit]

Tides may trigger some seismicity.[31]

Clusters

[edit]

Most earthquakes form part of a sequence, related to each other in terms of location and time.[32] Most earthquake clusters consist of small tremors that cause little to no damage, but there is a theory that earthquakes can recur in a regular pattern.[33] Earthquake clustering has been observed, for example, in Parkfield, California where a long-term research study is being conducted around the Parkfield earthquake cluster.[34]

Aftershocks

[edit]
Magnitude of the Central Italy earthquakes of August and October 2016 and January 2017 and the aftershocks (which continued to occur after the period shown here)

An aftershock is an earthquake that occurs after a previous earthquake, the mainshock. Rapid changes of stress between rocks, and the stress from the original earthquake are the main causes of these aftershocks,[35] along with the crust around the ruptured fault plane as it adjusts to the effects of the mainshock.[32] An aftershock is in the same region as the main shock but always of a smaller magnitude, however, they can still be powerful enough to cause even more damage to buildings that were already previously damaged from the mainshock.[35] If an aftershock is larger than the mainshock, the aftershock is redesignated as the mainshock and the original main shock is redesignated as a foreshock. Aftershocks are formed as the crust around the displaced fault plane adjusts to the effects of the mainshock.[32]

Swarms

[edit]

Earthquake swarms are sequences of earthquakes striking in a specific area within a short period. They are different from earthquakes followed by a series of aftershocks by the fact that no single earthquake in the sequence is the main shock, so none has a notably higher magnitude than another. An example of an earthquake swarm is the 2004 activity at Yellowstone National Park.[36] In August 2012, a swarm of earthquakes shook Southern California's Imperial Valley, showing the most recorded activity in the area since the 1970s.[37]

Sometimes a series of earthquakes occur in what has been called an earthquake storm, where the earthquakes strike a fault in clusters, each triggered by the shaking or stress redistribution of the previous earthquakes. Similar to aftershocks but on adjacent segments of fault, these storms occur over the course of years, with some of the later earthquakes as damaging as the early ones. Such a pattern was observed in the sequence of about a dozen earthquakes that struck the North Anatolian Fault in Turkey in the 20th century and has been inferred for older anomalous clusters of large earthquakes in the Middle East.[38][39]

Frequency

[edit]
The Messina earthquake and tsunami took about 80,000 lives on December 28, 1908, in Sicily and Calabria.[40]

It is estimated that around 500,000 earthquakes occur each year, detectable with current instrumentation. About 100,000 of these can be felt.[4][5] Minor earthquakes occur very frequently around the world in places like California and Alaska in the U.S., as well as in El Salvador, Mexico, Guatemala, Chile, Peru, Indonesia, the Philippines, Iran, Pakistan, the Azores in Portugal, Turkey, New Zealand, Greece, Italy, India, Nepal, and Japan.[41] Larger earthquakes occur less frequently, the relationship being exponential; for example, roughly ten times as many earthquakes larger than magnitude 4 occur than earthquakes larger than magnitude 5.[42] In the (low seismicity) United Kingdom, for example, it has been calculated that the average recurrences are: an earthquake of 3.7–4.6 every year, an earthquake of 4.7–5.5 every 10 years, and an earthquake of 5.6 or larger every 100 years.[43] This is an example of the Gutenberg–Richter law.

The number of seismic stations has increased from about 350 in 1931 to many thousands today. As a result, many more earthquakes are reported than in the past, but this is because of the vast improvement in instrumentation, rather than an increase in the number of earthquakes. The United States Geological Survey (USGS) estimates that, since 1900, there have been an average of 18 major earthquakes (magnitude 7.0–7.9) and one great earthquake (magnitude 8.0 or greater) per year, and that this average has been relatively stable.[44] In recent years, the number of major earthquakes per year has decreased, though this is probably a statistical fluctuation rather than a systematic trend.[45] More detailed statistics on the size and frequency of earthquakes is available from the United States Geological Survey.[46] A recent increase in the number of major earthquakes has been noted, which could be explained by a cyclical pattern of periods of intense tectonic activity, interspersed with longer periods of low intensity. However, accurate recordings of earthquakes only began in the early 1900s, so it is too early to categorically state that this is the case.[47]

Most of the world's earthquakes (90%, and 81% of the largest) take place in the 40,000-kilometre-long (25,000 mi), horseshoe-shaped zone called the circum-Pacific seismic belt, known as the Pacific Ring of Fire, which for the most part bounds the Pacific plate.[48][49] Massive earthquakes tend to occur along other plate boundaries too, such as along the Himalayan Mountains.[50]

With the rapid growth of mega-cities such as Mexico City, Tokyo, and Tehran in areas of high seismic risk, some seismologists are warning that a single earthquake may claim the lives of up to three million people.[51]

Induced seismicity

[edit]

While most earthquakes are caused by the movement of the Earth's tectonic plates, human activity can also produce earthquakes. Activities both above ground and below may change the stresses and strains on the crust, including building reservoirs, extracting resources such as coal or oil, and injecting fluids underground for waste disposal or fracking.[52] Most of these earthquakes have small magnitudes. The 5.7 magnitude 2011 Oklahoma earthquake is thought to have been caused by disposing wastewater from oil production into injection wells,[53] and studies point to the state's oil industry as the cause of other earthquakes in the past century.[54] A Columbia University paper suggested that the 8.0 magnitude 2008 Sichuan earthquake was induced by loading from the Zipingpu Dam,[55] though the link has not been conclusively proved.[56]

Measurement and location

[edit]

The instrumental scales used to describe the size of an earthquake began with the Richter scale in the 1930s. It is a relatively simple measurement of an event's amplitude, and its use has become minimal in the 21st century. Seismic waves travel through the Earth's interior and can be recorded by seismometers at great distances. The surface-wave magnitude was developed in the 1950s as a means to measure remote earthquakes and to improve the accuracy for larger events. The moment magnitude scale not only measures the amplitude of the shock but also takes into account the seismic moment (total rupture area, average slip of the fault, and rigidity of the rock). The Japan Meteorological Agency seismic intensity scale, the Medvedev–Sponheuer–Karnik scale, and the Mercalli intensity scale are based on the observed effects and are related to the intensity of shaking.

Intensity and magnitude

[edit]

The shaking of the earth is a common phenomenon that has been experienced by humans from the earliest of times. Before the development of strong-motion accelerometers, the intensity of a seismic event was estimated based on the observed effects. Magnitude and intensity are not directly related and calculated using different methods. The magnitude of an earthquake is a single value that describes the size of the earthquake at its source. Intensity is the measure of shaking at different locations around the earthquake. Intensity values vary from place to place, depending on the distance from the earthquake and the underlying rock or soil makeup.[57]

The first scale for measuring earthquake magnitudes was developed by Charles Francis Richter in 1935. Subsequent scales (seismic magnitude scales) have retained a key feature, where each unit represents a ten-fold difference in the amplitude of the ground shaking and a 32-fold difference in energy. Subsequent scales are also adjusted to have approximately the same numeric value within the limits of the scale.[58]

Although the mass media commonly reports earthquake magnitudes as "Richter magnitude" or "Richter scale", standard practice by most seismological authorities is to express an earthquake's strength on the moment magnitude scale, which is based on the actual energy released by an earthquake, the static seismic moment.[59][60]

Seismic waves

[edit]

Every earthquake produces different types of seismic waves, which travel through rock with different velocities:

Speed of seismic waves

[edit]

Propagation velocity of the seismic waves through solid rock ranges from approx. 3 km/s (1.9 mi/s) up to 13 km/s (8.1 mi/s), depending on the density and elasticity of the medium. In the Earth's interior, the shock- or P waves travel much faster than the S waves (approx. relation 1.7:1). The differences in travel time from the epicenter to the observatory are a measure of the distance and can be used to image both sources of earthquakes and structures within the Earth. Also, the depth of the hypocenter can be computed roughly.

P wave speed

  • Upper crust soils and unconsolidated sediments: 2–3 km (1.2–1.9 mi) per second
  • Upper crust solid rock: 3–6 km (1.9–3.7 mi) per second
  • Lower crust: 6–7 km (3.7–4.3 mi) per second
  • Deep mantle: 13 km (8.1 mi) per second.

S waves speed

  • Light sediments: 2–3 km (1.2–1.9 mi) per second
  • Earths crust: 4–5 km (2.5–3.1 mi) per second
  • Deep mantle: 7 km (4.3 mi) per second

Seismic wave arrival

[edit]

As a consequence, the first waves of a distant earthquake arrive at an observatory via the Earth's mantle.

On average, the kilometer distance to the earthquake is the number of seconds between the P- and S wave arrival times, multiplied by 8.[61] Slight deviations are caused by inhomogeneities of subsurface structure. By such analysis of seismograms, the Earth's core was located in 1913 by Beno Gutenberg.

S waves and later arriving surface waves do most of the damage compared to P waves. P waves squeeze and expand the material in the same direction they are traveling, whereas S waves shake the ground up and down and back and forth.[62]

Location and reporting

[edit]

Earthquakes are not only categorized by their magnitude but also by the place where they occur. The world is divided into 754 Flinn–Engdahl regions (F-E regions), which are based on political and geographical boundaries as well as seismic activity. More active zones are divided into smaller F-E regions whereas less active zones belong to larger F-E regions.

Standard reporting of earthquakes includes its magnitude, date and time of occurrence, geographic coordinates of its epicenter, depth of the epicenter, geographical region, distances to population centers, location uncertainty, several parameters that are included in USGS earthquake reports (number of stations reporting, number of observations, etc.), and a unique event ID.[63]

Although relatively slow seismic waves have traditionally been used to detect earthquakes, scientists realized in 2016 that gravitational measurement could provide instantaneous detection of earthquakes, and confirmed this by analyzing gravitational records associated with the 2011 Tohoku-Oki ("Fukushima") earthquake.[64][65]

Effects

[edit]
1755 copper engraving depicting Lisbon in ruins and in flames after the 1755 Lisbon earthquake, which killed an estimated 60,000 people. A tsunami overwhelms the ships in the harbor.

The effects of earthquakes include, but are not limited to, the following:

Shaking and ground rupture

[edit]
Damaged buildings in Port-au-Prince, Haiti, January 2010

Shaking and ground rupture are the main effects created by earthquakes, principally resulting in more or less severe damage to buildings and other rigid structures. The severity of the local effects depends on the complex combination of the earthquake magnitude, the distance from the epicenter, and the local geological and geomorphological conditions, which may amplify or reduce wave propagation.[66] The ground-shaking is measured by ground acceleration.

Specific local geological, geomorphological, and geostructural features can induce high levels of shaking on the ground surface even from low-intensity earthquakes. This effect is called site or local amplification. It is principally due to the transfer of the seismic motion from hard deep soils to soft superficial soils and the effects of seismic energy focalization owing to the typical geometrical setting of such deposits.

Ground rupture is a visible breaking and displacement of the Earth's surface along the trace of the fault, which may be of the order of several meters in the case of major earthquakes. Ground rupture is a major risk for large engineering structures such as dams, bridges, and nuclear power stations and requires careful mapping of existing faults to identify any that are likely to break the ground surface within the life of the structure.[67]

Soil liquefaction

[edit]

Soil liquefaction occurs when, because of the shaking, water-saturated granular material (such as sand) temporarily loses its strength and transforms from a solid to a liquid. Soil liquefaction may cause rigid structures, like buildings and bridges, to tilt or sink into the liquefied deposits. For example, in the 1964 Alaska earthquake, soil liquefaction caused many buildings to sink into the ground, eventually collapsing upon themselves.[68]

Human impacts

[edit]
Ruins of the Għajn Ħadid Tower, which collapsed during the 1856 Heraklion earthquake

Physical damage from an earthquake will vary depending on the intensity of shaking in a given area and the type of population. Underserved and developing communities frequently experience more severe impacts (and longer lasting) from a seismic event compared to well-developed communities.[69] Impacts may include:

  • Injuries and loss of life
  • Damage to critical infrastructure (short and long-term)
    • Roads, bridges, and public transportation networks
    • Water, power, sewer and gas interruption
    • Communication systems
  • Loss of critical community services including hospitals, police, and fire
  • General property damage
  • Collapse or destabilization (potentially leading to future collapse) of buildings

With these impacts and others, the aftermath may bring disease, a lack of basic necessities, mental consequences such as panic attacks and depression to survivors,[70] and higher insurance premiums. Recovery times will vary based on the level of damage and the socioeconomic status of the impacted community.

Landslides

[edit]

China stood out in several categories in a study group of 162 earthquakes (from 1772 to 2021) that included landslide fatalities. Due to the 2008 Sichuan earthquake, it had 42% of all landslide fatalities within the study (total event deaths were higher). They were followed by Peru (22%) from the 1970 Ancash earthquake, and Pakistan (21%) from the 2005 Kashmir earthquake. China was also on top with the highest area affected by landslides with more than 80,000 km2, followed by Canada with 66,000 km2 (1988 Saguenay and 1946 Vancouver Island). Strike-slip (61 events) was the dominant fault type listed, followed closely by thrust/reverse (57), and normal (33).[71]

Fires

[edit]
Fires of the 1906 San Francisco earthquake

Earthquakes can cause fires by damaging electrical power or gas lines. In the event of water mains rupturing and a loss of pressure, it may also become difficult to stop the spread of a fire once it has started. For example, more deaths in the 1906 San Francisco earthquake were caused by fire than by the earthquake itself.[72]

Tsunami

[edit]
The tsunami of the 2004 Indian Ocean earthquake

Tsunamis are long-wavelength, long-period sea waves produced by the sudden or abrupt movement of large volumes of water—including when an earthquake occurs at sea. In the open ocean, the distance between wave crests can surpass 100 kilometres (62 mi), and the wave periods can vary from five minutes to one hour. Such tsunamis travel 600–800 kilometers per hour (373–497 miles per hour), depending on water depth. Large waves produced by an earthquake or a submarine landslide can overrun nearby coastal areas in a matter of minutes. Tsunamis can also travel thousands of kilometers across open ocean and wreak destruction on far shores hours after the earthquake that generated them.[73]

Ordinarily, subduction earthquakes under magnitude 7.5 do not cause tsunamis, although some instances of this have been recorded. Most destructive tsunamis are caused by earthquakes of magnitude 7.5 or more.[73]

Floods

[edit]

Floods may be secondary effects of earthquakes if dams are damaged. Earthquakes may cause landslips to dam rivers, which collapse and cause floods.[74]

The terrain below the Sarez Lake in Tajikistan is in danger of catastrophic flooding if the landslide dam formed by the earthquake, known as the Usoi Dam, were to fail during a future earthquake. Impact projections suggest the flood could affect roughly five million people.[75]

Management

[edit]

Prediction

[edit]

Earthquake prediction is a branch of the science of seismology concerned with the specification of the time, location, and magnitude of future earthquakes within stated limits.[76] Many methods have been developed for predicting the time and place in which earthquakes will occur. Despite considerable research efforts by seismologists, scientifically reproducible predictions cannot yet be made to a specific day or month.[77] Popular belief holds earthquakes are preceded by earthquake weather, in the early morning.[78][79]

Forecasting

[edit]

While forecasting is usually considered to be a type of prediction, earthquake forecasting is often differentiated from earthquake prediction. Earthquake forecasting is concerned with the probabilistic assessment of general earthquake hazards, including the frequency and magnitude of damaging earthquakes in a given area over years or decades.[80] For well-understood faults the probability that a segment may rupture during the next few decades can be estimated.[81][82]

Earthquake warning systems have been developed that can provide regional notification of an earthquake in progress, but before the ground surface has begun to move, potentially allowing people within the system's range to seek shelter before the earthquake's impact is felt.

Preparedness

[edit]

The objective of earthquake engineering is to foresee the impact of earthquakes on buildings, bridges, tunnels, roadways, and other structures, and to design such structures to minimize the risk of damage. Existing structures can be modified by seismic retrofitting to improve their resistance to earthquakes. Earthquake insurance can provide building owners with financial protection against losses resulting from earthquakes. Emergency management strategies can be employed by a government or organization to mitigate risks and prepare for consequences.

Artificial intelligence may help to assess buildings and plan precautionary operations. The Igor expert system is part of a mobile laboratory that supports the procedures leading to the seismic assessment of masonry buildings and the planning of retrofitting operations on them. It has been applied to assess buildings in Lisbon, Rhodes, and Naples.[83]

Individuals can also take preparedness steps like securing water heaters and heavy items that could injure someone, locating shutoffs for utilities, and being educated about what to do when the shaking starts. For areas near large bodies of water, earthquake preparedness encompasses the possibility of a tsunami caused by a large earthquake.

In culture

[edit]
An image from a 1557 book depicting an earthquake in Italy in the 4th century BCE

From the lifetime of the Greek philosopher Anaxagoras in the 5th century BCE to the 14th century CE, earthquakes were usually attributed to "air (vapors) in the cavities of the Earth."[84] Pliny the Elder called earthquakes "underground thunderstorms".[84] Thales of Miletus (625–547 BCE) was the only documented person who believed that earthquakes were caused by tension between the earth and water.[84]

In Norse mythology, earthquakes were explained as the violent struggle of the god Loki being punished for the murder of Baldr, god of beauty and light.[85] In Greek mythology, Poseidon was the cause and god of earthquakes.[86] In Japanese mythology, Namazu (鯰) is a giant catfish who causes earthquakes.[87] In Taiwanese folklore, the TÄ“-gû (地牛) is a giant earth buffalo who causes earthquakes.[88]

In the New Testament, Matthew's Gospel refers to earthquakes occurring both after the death of Jesus (Matthew 27:51, 54) and at his resurrection (Matthew 28:2).[89]

In modern popular culture, the portrayal of earthquakes is shaped by the memory of great cities laid waste, such as Kobe in 1995 or San Francisco in 1906.[90] Fictional earthquakes tend to strike suddenly and without warning.[90] For this reason, stories about earthquakes generally begin with the disaster and focus on its immediate aftermath, as in Short Walk to Daylight (1972), The Ragged Edge (1968) or Aftershock: Earthquake in New York (1999).[90] A notable example is Heinrich von Kleist's classic novella, The Earthquake in Chile, which describes the destruction of Santiago in 1647. Haruki Murakami's short fiction collection After the Quake depicts the consequences of the Kobe earthquake of 1995.

The most popular single earthquake in fiction is the hypothetical "Big One" expected of California's San Andreas Fault someday, as depicted in the novels Richter 10 (1996), Goodbye California (1977), 2012 (2009), and San Andreas (2015), among other works.[90]

Outside of Earth

[edit]

Phenomena similar to earthquakes have been observed on other planets (e.g., marsquakes on Mars) and on the Moon (e.g., moonquakes).

See also

[edit]

References

[edit]
  1. ^ "USGS: Magnitude 8 and Greater Earthquakes Since 1900". Archived from the original on April 14, 2016.
  2. ^ "Earthquakes with 50,000 or More Deaths". United States Geological Survey. Archived from the original on November 1, 2009.
  3. ^ Spignesi, Stephen J. (2005). Catastrophe!: The 100 Greatest Disasters of All Time. ISBN 0-8065-2558-4
  4. ^ a b "Cool Earthquake Facts". United States Geological Survey. Archived from the original on 2021-04-20. Retrieved 2021-04-21.
  5. ^ a b Pressler, Margaret Webb (14 April 2010). "More earthquakes than usual? Not really". KidsPost. The Washington Post. pp. C10.
  6. ^ Kanamori Hiroo. "The Energy Release in Great Earthquakes" (PDF). Journal of Geophysical Research. Archived from the original (PDF) on 2010-07-23. Retrieved 2010-10-10.
  7. ^ "How Much Bigger?". United States Geological Survey. Archived from the original on 2011-06-07. Retrieved 2010-10-10.
  8. ^ Ohnaka, M. (2013). The Physics of Rock Failure and Earthquakes. Cambridge University Press. p. 148. ISBN 978-1-107-35533-0.
  9. ^ Vassiliou, Marius; Kanamori, Hiroo (1982). "The Energy Release in Earthquakes". Bull. Seismol. Soc. Am. 72: 371–387.
  10. ^ Spence, William; S.A. Sipkin; G.L. Choy (1989). "Measuring the Size of an Earthquake". United States Geological Survey. Archived from the original on 2009-09-01. Retrieved 2006-11-03.
  11. ^ Sibson, R.H. (1982). "Fault Zone Models, Heat Flow, and the Depth Distribution of Earthquakes in the Continental Crust of the United States". Bulletin of the Seismological Society of America. 72 (1): 151–163.
  12. ^ Sibson, R.H. (2002) "Geology of the crustal earthquake source" International handbook of earthquake and engineering seismology, Volume 1, Part 1, p. 455, eds. W H K Lee, H Kanamori, P C Jennings, and C. Kisslinger, Academic Press, ISBN 978-0-12-440652-0
  13. ^ Hjaltadóttir S., 2010, "Use of relatively located microearthquakes to map fault patterns and estimate the thickness of the brittle crust in Southwest Iceland"
  14. ^ "Reports and publications | Seismicity | Icelandic Meteorological office". En.vedur.is. Archived from the original on 2008-04-14. Retrieved 2011-07-24.
  15. ^ Stern, Robert J. (2002), "Subduction zones", Reviews of Geophysics, 40 (4): 17, Bibcode:2002RvGeo..40.1012S, doi:10.1029/2001RG000108, S2CID 247695067
  16. ^ "Instrumental California Earthquake Catalog". WGCEP. Archived from the original on 2011-07-25. Retrieved 2011-07-24.
  17. ^ Schorlemmer, D.; Wiemer, S.; Wyss, M. (2005). "Variations in earthquake-size distribution across different stress regimes". Nature. 437 (7058): 539–542. Bibcode:2005Natur.437..539S. doi:10.1038/nature04094. PMID 16177788. S2CID 4327471.
  18. ^ Geoscience Australia.[full citation needed]
  19. ^ Wyss, M. (1979). "Estimating expectable maximum magnitude of earthquakes from fault dimensions". Geology. 7 (7): 336–340. Bibcode:1979Geo.....7..336W. doi:10.1130/0091-7613(1979)7<336:EMEMOE>2.0.CO;2.
  20. ^ "Global Centroid Moment Tensor Catalog". Globalcmt.org. Archived from the original on 2011-07-19. Retrieved 2011-07-24.
  21. ^ "M7.5 Northern Peru Earthquake of 26 September 2005" (PDF). National Earthquake Information Center. 17 October 2005. Archived from the original (PDF) on 2017-05-25. Retrieved 2008-08-01.
  22. ^ Greene II, H.W.; Burnley, P.C. (October 26, 1989). "A new self-organizing mechanism for deep-focus earthquakes". Nature. 341 (6244): 733–737. Bibcode:1989Natur.341..733G. doi:10.1038/341733a0. S2CID 4287597.
  23. ^ Foxworthy and Hill (1982). Volcanic Eruptions of 1980 at Mount St. Helens, The First 100 Days: USGS Professional Paper 1249.
  24. ^ Watson, John; Watson, Kathie (January 7, 1998). "Volcanoes and Earthquakes". United States Geological Survey. Archived from the original on March 26, 2009. Retrieved May 9, 2009.
  25. ^ a b National Research Council (U.S.). Committee on the Science of Earthquakes (2003). "5. Earthquake Physics and Fault-System Science". Living on an Active Earth: Perspectives on Earthquake Science. Washington, D.C.: National Academies Press. p. 418. ISBN 978-0-309-06562-7. Retrieved 8 July 2010.
  26. ^ Melgar, Diego; Taymaz, Tuncay; Ganas, Athanassios; Crowell, Brendan; Öcalan, Taylan; Kahraman, Metin; Tsironi, Varvara; Yolsal-Çevikbilen, Seda; Valkaniotis, Sotiris; Irmak, Tahir Serkan; Eken, Tuna; Erman, Ceyhun; Özkan, Berkan; Dogan, Ali Hasan; AltuntaÅŸ, Cemali (2023). "Sub- and super-shear ruptures during the 2023 Mw 7.8 and Mw 7.6 earthquake doublet in SE Türkiye". Seismica. 2 (3): 387. Bibcode:2023Seism...2..387M. doi:10.26443/seismica.v2i3.387. S2CID 257520761.
  27. ^ Sibson, R.H. (1973). "Interactions between Temperature and Pore-Fluid Pressure during Earthquake Faulting and a Mechanism for Partial or Total Stress Relief". Nat. Phys. Sci. 243 (126): 66–68. Bibcode:1973NPhS..243...66S. doi:10.1038/physci243066a0.
  28. ^ Rudnicki, J.W.; Rice, J.R. (2006). "Effective normal stress alteration due to pore pressure changes induced by dynamic slip propagation on a plane between dissimilar materials" (PDF). J. Geophys. Res. 111, B10308 (B10). Bibcode:2006JGRB..11110308R. doi:10.1029/2006JB004396. S2CID 1333820. Archived (PDF) from the original on 2019-05-02.
  29. ^ a b c Guerriero, V; Mazzoli, S. (2021). "Theory of Effective Stress in Soil and Rock and Implications for Fracturing Processes: A Review". Geosciences. 11 (3): 119. Bibcode:2021Geosc..11..119G. doi:10.3390/geosciences11030119.
  30. ^ a b Nur, A; Booker, J.R. (1972). "Aftershocks Caused by Pore Fluid Flow?". Science. 175 (4024): 885–887. Bibcode:1972Sci...175..885N. doi:10.1126/science.175.4024.885. PMID 17781062. S2CID 19354081.
  31. ^ Hartzell, Stephen; Heaton, Thomas (1990-04-01). "The fortnightly tide and the tidal triggering of earthquakes" (PDF). Bulletin of the Seismological Society of America. 80 (2): 504–505. Bibcode:1990BuSSA..80..504H. doi:10.1785/BSSA0800020504. ISSN 1943-3573.
  32. ^ a b c "What are Aftershocks, Foreshocks, and Earthquake Clusters?". Archived from the original on 2009-05-11.
  33. ^ "Repeating Earthquakes". United States Geological Survey. January 29, 2009. Archived from the original on April 3, 2009. Retrieved May 11, 2009.
  34. ^ "The Parkfield, California, Earthquake Experiment". United States Geological Survey. Archived from the original on 2022-10-24. Retrieved 2022-10-24.
  35. ^ a b "Aftershock | geology". Encyclopædia Britannica. Archived from the original on 2015-08-23. Retrieved 2021-10-13.
  36. ^ "Earthquake Swarms at Yellowstone". United States Geological Survey. Archived from the original on 2008-05-13. Retrieved 2008-09-15.
  37. ^ Duke, Alan. "Quake 'swarm' shakes Southern California". CNN. Archived from the original on 27 August 2012. Retrieved 27 August 2012.
  38. ^ Amos Nur; Cline, Eric H. (2000). "Poseidon's Horses: Plate Tectonics and Earthquake Storms in the Late Bronze Age Aegean and Eastern Mediterranean" (PDF). Journal of Archaeological Science. 27 (1): 43–63. Bibcode:2000JArSc..27...43N. doi:10.1006/jasc.1999.0431. ISSN 0305-4403. Archived from the original (PDF) on 2009-03-25.
  39. ^ "Earthquake Storms". Horizon. 1 April 2003. Archived from the original on 2019-10-16. Retrieved 2007-05-02.
  40. ^ Guidoboni E.; Ferrari G.; Mariotti D.; Comastri A.; Tarabusi G.; Sgattoni G.; Valensise G. "1908 12 28, 04:20:27 Calabria meridionale-Messina (Italy)". CFTI5 Catalogue of Strong Earthquakes in Italy (461 BC – 1997) and Mediterranean Area (760 B.C. – 1500).
  41. ^ "Earthquake Hazards Program". United States Geological Survey. Archived from the original on 2011-05-13. Retrieved 2006-08-14.
  42. ^ "USGS Earthquake statistics table based on data since 1900". Archived from the original on May 24, 2010.
  43. ^ "Seismicity and earthquake hazard in the UK". Quakes.bgs.ac.uk. Archived from the original on 2010-11-06. Retrieved 2010-08-23.
  44. ^ "Common Myths about Earthquakes". United States Geological Survey. Archived from the original on 2006-09-25. Retrieved 2006-08-14.
  45. ^ Are Earthquakes Really on the Increase? Archived 2014-06-30 at the Wayback Machine, USGS Science of Changing World. Retrieved 30 May 2014.
  46. ^ "Earthquake Facts and Statistics: Are earthquakes increasing?". United States Geological Survey. Archived from the original on 2006-08-12. Retrieved 2006-08-14.
  47. ^ The 10 biggest earthquakes in history Archived 2013-09-30 at the Wayback Machine, Australian Geographic, March 14, 2011.
  48. ^ "Historic Earthquakes and Earthquake Statistics: Where do earthquakes occur?". United States Geological Survey. Archived from the original on 2006-09-25. Retrieved 2006-08-14.
  49. ^ "Visual Glossary – Ring of Fire". United States Geological Survey. Archived from the original on 2006-08-28. Retrieved 2006-08-14.
  50. ^ Jackson, James (2006). "Fatal attraction: living with earthquakes, the growth of villages into megacities, and earthquake vulnerability in the modern world". Philosophical Transactions of the Royal Society. 364 (1845): 1911–1925. Bibcode:2006RSPTA.364.1911J. doi:10.1098/rsta.2006.1805. PMID 16844641. S2CID 40712253. Archived from the original on 2013-09-03. Retrieved 2011-03-09.
  51. ^ "Global urban seismic risk Archived 2011-09-20 at the Wayback Machine." Cooperative Institute for Research in Environmental Science.
  52. ^ Fougler, Gillian R.; Wilson, Miles; Gluyas, Jon G.; Julian, Bruce R.; Davies, Richard J. (2018). "Global review of human-induced earthquakes". Earth-Science Reviews. 178: 438–514. Bibcode:2018ESRv..178..438F. doi:10.1016/j.earscirev.2017.07.008.
  53. ^ Fountain, Henry (March 28, 2013). "Study Links 2011 Quake to Technique at Oil Wells". The New York Times. Archived from the original on July 23, 2020. Retrieved July 23, 2020.
  54. ^ Hough, Susan E.; Page, Morgan (2015). "A Century of Induced Earthquakes in Oklahoma?". Bulletin of the Seismological Society of America. 105 (6): 2863–2870. Bibcode:2015BuSSA.105.2863H. doi:10.1785/0120150109. Archived from the original on July 23, 2020. Retrieved July 23, 2020.
  55. ^ Klose, Christian D. (July 2012). "Evidence for anthropogenic surface loading as trigger mechanism of the 2008 Wenchuan earthquake". Environmental Earth Sciences. 66 (5): 1439–1447. arXiv:1007.2155. Bibcode:2012EES....66.1439K. doi:10.1007/s12665-011-1355-7. S2CID 118367859.
  56. ^ LaFraniere, Sharon (February 5, 2009). "Possible Link Between Dam and China Quake". The New York Times. Archived from the original on January 27, 2018. Retrieved July 23, 2020.
  57. ^ Earle, Steven (September 2015). "11.3 Measuring Earthquakes". Physical Geology (2nd ed.). Archived from the original on 2022-10-21. Retrieved 2022-10-22.
  58. ^ Chung & Bernreuter 1980, p. 1.
  59. ^ "USGS Earthquake Magnitude Policy (implemented on January 18, 2002)". United States Geological Survey. Archived from the original on 2016-05-04. A copy can be found at "USGS Earthquake Magnitude Policy". Archived from the original on 2017-07-31. Retrieved 2017-07-25.
  60. ^ Bormann, P; Di Giacomo, D (2011). "The moment magnitude Mw and the energy magnitude Me: common roots and differences". Journal of Seismology. 15 (2): 411–427. doi:10.1007/s10950-010-9219-2 – via Springer Link.
  61. ^ "Speed of Sound through the Earth". Hypertextbook.com. Archived from the original on 2010-11-25. Retrieved 2010-08-23.
  62. ^ "Newsela | The science of earthquakes". newsela.com. Archived from the original on 2017-03-01. Retrieved 2017-02-28.
  63. ^ Geographic.org. "Magnitude 8.0 – SANTA CRUZ ISLANDS Earthquake Details". Global Earthquake Epicenters with Maps. Archived from the original on 2013-05-14. Retrieved 2013-03-13.
  64. ^ "Earth's gravity offers earlier earthquake warnings". Archived from the original on 2016-11-23. Retrieved 2016-11-22.
  65. ^ "Gravity shifts could sound early earthquake alarm". Archived from the original on 2016-11-24. Retrieved 2016-11-23.
  66. ^ "On Shaky Ground, Association of Bay Area Governments, San Francisco, reports 1995, 1998 (updated 2003)". Abag.ca.gov. Archived from the original on 2009-09-21. Retrieved 2010-08-23.
  67. ^ "Guidelines for evaluating the hazard of surface fault rupture, California Geological Survey" (PDF). California Department of Conservation. 2002. Archived from the original (PDF) on 2009-10-09.
  68. ^ "Historic Earthquakes – 1964 Anchorage Earthquake". United States Geological Survey. Archived from the original on 2011-06-23. Retrieved 2008-09-15.
  69. ^ "The wicked problem of earthquake hazard in developing countries". preventionweb.net. 7 March 2018. Archived from the original on 2022-11-03. Retrieved 2022-11-03.
  70. ^ "Earthquake Resources". Nctsn.org. 30 January 2018. Archived from the original on 2018-03-21. Retrieved 2018-06-05.
  71. ^ Seal, Dylan M; Jessee, Anna Nowicki; Hamburger, Michael; Dills, Carter; Allstadt, Kate E (2022), Comprehensive Global Database of Earthquake-Induced Landslide Events and Their Impacts (ver. 2.0, February 2022), U.S. Geological Survey, doi:10.5066/P9RG3MBE
  72. ^ "The Great 1906 San Francisco earthquake of 1906". United States Geological Survey. Archived from the original on 2017-02-11. Retrieved 2008-09-15.
  73. ^ a b Noson, L.L.; Qamar, A.; Thorsen, G.W. (1988). Washington Division of Geology and Earth Resources Information Circular 85 (PDF). Washington State Earthquake Hazards. Archived (PDF) from the original on 2020-02-04. Retrieved 2019-12-01.
  74. ^ "Notes on Historical Earthquakes". British Geological Survey. Archived from the original on 2011-05-16. Retrieved 2008-09-15.
  75. ^ "Fresh alert over Tajik flood threat". BBC News. 2003-08-03. Archived from the original on 2008-11-22. Retrieved 2008-09-15.
  76. ^ Geller et al. 1997, p. 1616, following Allen (1976, p. 2070), who in turn followed Wood & Gutenberg (1935)
  77. ^ Earthquake Prediction Archived 2009-10-07 at the Wayback Machine. Ruth Ludwin, U.S. Geological Survey.
  78. ^ Lafee, Scott (April 9, 2010). "Quake myths rely on cloudy facts". The San Diego Union-Tribune. Retrieved July 3, 2024.
  79. ^ "Is there earthquake weather?". United States Geological Survey. Archived from the original on March 3, 2024. Retrieved July 3, 2024.
  80. ^ Kanamori 2003, p. 1205. See also International Commission on Earthquake Forecasting for Civil Protection 2011, p. 327.
  81. ^ Working Group on California Earthquake Probabilities in the San Francisco Bay Region, 2003 to 2032, 2003, "Bay Area Earthquake Probabilities". Archived from the original on 2017-02-18. Retrieved 2017-08-28.
  82. ^ Pailoplee, Santi (2017-03-13). "Probabilities of Earthquake Occurrences along the Sumatra-Andaman Subduction Zone". Open Geosciences. 9 (1): 4. Bibcode:2017OGeo....9....4P. doi:10.1515/geo-2017-0004. ISSN 2391-5447. S2CID 132545870.
  83. ^ Salvaneschi, P.; Cadei, M.; Lazzari, M. (1996). "Applying AI to Structural Safety Monitoring and Evaluation". IEEE Expert. 11 (4): 24–34. doi:10.1109/64.511774.
  84. ^ a b c "Earthquakes". Encyclopedia of World Environmental History. Vol. 1: A–G. Routledge. 2003. pp. 358–364.
  85. ^ Sturluson, Snorri (1220). Prose Edda. General Books. ISBN 978-1-156-78621-5. cite book: ISBN / Date incompatibility (help)
  86. ^ George E. Dimock (1990). The Unity of the Odyssey. Univ of Massachusetts Press. p. 179. ISBN 978-0-87023-721-8.
  87. ^ "Namazu". World History Encyclopedia. Retrieved 2017-07-23.
  88. ^ "Earthquake Island, Taiwan: The Ground Buffalo Myth, Deities and Earthquakes". ARTouch. 14 June 2024. Retrieved 2025-05-05.
  89. ^ Allison, D., 56. Matthew, in Barton, J. and Muddiman, J. (2001), The Oxford Bible Commentary Archived 2017-11-22 at the Wayback Machine, p. 884
  90. ^ a b c d Van Riper, A. Bowdoin (2002). Science in popular culture: a reference guide. Westport: Greenwood Press. p. 60. ISBN 978-0-313-31822-1.

Sources

[edit]

Further reading

[edit]
[edit]

 

A catastrophic failure is a sudden and total failure from which recovery is impossible. Catastrophic failures often lead to cascading systems failure. The term is most commonly used for structural failures, but has often been extended to many other disciplines in which total and irrecoverable loss occurs, such as a head crash occurrence on a hard disk drive.

For example, catastrophic failure can be observed in steam turbine rotor failure, which can occur due to peak stress on the rotor; stress concentration increases up to a point at which it is excessive, leading ultimately to the failure of the disc.

In firearms, catastrophic failure usually refers to a rupture or disintegration of the barrel or receiver of the gun when firing it. Some possible causes of this are an out-of-battery gun, an inadequate headspace, the use of incorrect ammunition, the use of ammunition with an incorrect propellant charge,[1] a partially or fully obstructed barrel,[2] or weakened metal in the barrel or receiver. A failure of this type, known colloquially as a "kaboom", or "kB" failure, can pose a threat not only to the user(s) but even many bystanders.

In chemical engineering, a reaction which undergoes thermal runaway can cause catastrophic failure.

It can be difficult to isolate the cause or causes of a catastrophic failure from other damage that occurred during the failure. Forensic engineering and failure analysis deal with finding and analysing these causes.

Examples

[edit]
Original Tay Bridge from the north
Fallen Tay Bridge from the north

Examples of catastrophic failure of engineered structures include:

  • The Tay Rail Bridge disaster of 1879, where the center 0.5 miles (0.80 km) of the bridge was completely destroyed while a train was crossing in a storm. The bridge was inadequately designed and its replacement was built as a separate structure upstream of the old.
  • The failure of the South Fork Dam in 1889 released 4.8 billion US gallons (18 billion litres) of water and killed over 2,200 people (popularly known as the Johnstown Flood).
  • The collapse of the St. Francis Dam in 1928 released 12.4 billion US gallons (47 billion litres) of water, resulting in a death toll of nearly 600 people.
  • The collapse of the first Tacoma Narrows Bridge of 1940, where the main deck of the road bridge was totally destroyed by dynamic oscillations in a 40 mph (64 km/h) wind.
  • The De Havilland Comet disasters of 1954, later determined to be structural failures due to greater metal fatigue than anticipated at the corners of windows.
  • The failure of the Banqiao Dam and 61 others in China in 1975, due to Typhoon Nina. Approximately 86,000 people died from flooding and another 145,000 died from subsequent diseases, a total of 231,000 deaths.
  • The Hyatt Regency walkway collapse of 1981, where a suspended walkway in a hotel lobby in Kansas City, Missouri, collapsed completely, killing over 100 people on and below the structure.
  • The Space Shuttle Challenger disaster of 1986, in which an O-ring of a rocket booster failed, causing the external fuel tank to break up and making the shuttle veer off course, subjecting it to aerodynamic forces beyond design tolerances; the entire crew of 7 and vehicle were lost.
  • The nuclear reactor at the Chernobyl power plant, which exploded in April 26, 1986 causing the release of a substantial amount of radioactive materials.
  • The collapse of the Warsaw radio mast of 1991, which had up to that point held the title of world's tallest structure.
  • The Sampoong Department Store collapse of 1995, which happened due to structural weaknesses, killed 502 people and injured 937.
  • The terrorist attacks and subsequent fire at the World Trade Center on September 11, 2001, weakened the floor joists to the point of catastrophic failure.
  • The Space Shuttle Columbia disaster of 2003, where damage to a wing during launch resulted in total loss upon re-entry.
  • The collapse of the multi-span I-35W Mississippi River bridge on August 1, 2007.
  • The collapse of the Olivos-Tezonco Mexico City Metro overpass of 2021, which had structurally weakened over the years.

See also

[edit]
  • Dragon King Theory
  • List of bridge disasters
  • Progressive collapse
  • Seismic performance
  • Structural collapse
  • Structural failure
  • Resonance disaster
  • Risks to civilization, humans and planet Earth

References

[edit]
  1. ^ Hal W. Hendrick; Paul Paradis; Richard J. Hornick (2010). Human Factors Issues in Handgun Safety and Forensics. CRC Press. p. 132. ISBN 978-1420062977. Retrieved 2014-02-24. Many firearms are destroyed and injuries sustained by home reloaders who make a mistake in estimating the correct powder charge.
  2. ^ Gregg Lee Carter, ed. (2012). Guns in American Society. ABC-CLIO. p. 255. ISBN 978-0-313-38670-1. Retrieved 2014-02-24. ... and left the copper jacket lodged in the barrel, leading to a catastrophic failuer of the rifle when the next bullet fired hit the jacket remnants.

Further reading

[edit]
  • Feynman, Richard; Leighton, Ralph (1988). What Do You Care What Other People Think?. W. W. Norton. ISBN 0-553-17334-0.
  • Lewis, Peter R. (2004). Beautiful Railway Bridge of the Silvery Tay: Reinvestigating the Tay Bridge Disaster of 1879. Tempus. ISBN 0-7524-3160-9.

About United Structural Systems of Illinois

Driving Directions in Cook County


Structural Foundation Repair
42.047538049027, -88.156119464192
Starting Point
United Structural Systems of Illinois, 2124 Stonington Ave, Hoffman Estates, IL 60169, USA
Destination
Open in Google Maps
bowing foundation walls
42.039267787566, -88.08686997854
Starting Point
United Structural Systems of Illinois, 2124 Stonington Ave, Hoffman Estates, IL 60169, USA
Destination
Open in Google Maps
residential waterproofing services
42.093723466038, -88.081975094279
Starting Point
United Structural Systems of Illinois, 2124 Stonington Ave, Hoffman Estates, IL 60169, USA
Destination
Open in Google Maps
permanent foundation repair
42.031516728826, -88.132768551546
Starting Point
United Structural Systems of Illinois, 2124 Stonington Ave, Hoffman Estates, IL 60169, USA
Destination
Open in Google Maps
basement waterproofing Cook County
42.034321541103, -88.17062131774
Starting Point
United Structural Systems of Illinois, 2124 Stonington Ave, Hoffman Estates, IL 60169, USA
Destination
Open in Google Maps
expert foundation repair Hoffman Estates
42.098101823459, -88.111844334127
Starting Point
United Structural Systems of Illinois, 2124 Stonington Ave, Hoffman Estates, IL 60169, USA
Destination
Open in Google Maps
comprehensive foundation repair
42.106569617967, -88.15402951347
Starting Point
United Structural Systems of Illinois, 2124 Stonington Ave, Hoffman Estates, IL 60169, USA
Destination
Open in Google Maps
home foundation protection
42.031060547635, -88.10000117987
Starting Point
United Structural Systems of Illinois, 2124 Stonington Ave, Hoffman Estates, IL 60169, USA
Destination
Open in Google Maps
helical wall tieback anchors
42.014047754937, -88.116603094124
Starting Point
United Structural Systems of Illinois, 2124 Stonington Ave, Hoffman Estates, IL 60169, USA
Destination
Open in Google Maps
Cook County foundation repair
42.077352972693, -88.10039001905
Starting Point
United Structural Systems of Illinois, 2124 Stonington Ave, Hoffman Estates, IL 60169, USA
Destination
Open in Google Maps
Google Maps Location
https://www.google.com/maps/dir/?api=1&origin=42.047989288019,-88.077983664751&destination=United+Structural+Systems+of+Illinois%2C+2124+Stonington+Ave%2C+Hoffman+Estates%2C+IL+60169%2C+USA&destination_place_id=ChIJ-wSxDtinD4gRiv4kY3RRh9U&travelmode=driving&query=Chicagoland+foundation+crack+repair
Click below to open this location on Google Maps
Google Maps Location
https://www.google.com/maps/dir/?api=1&origin=42.088315487954,-88.183549200532&destination=United+Structural+Systems+of+Illinois%2C+2124+Stonington+Ave%2C+Hoffman+Estates%2C+IL+60169%2C+USA&destination_place_id=ChIJ-wSxDtinD4gRiv4kY3RRh9U&travelmode=driving&query=Illinois+foundation+solutions
Click below to open this location on Google Maps
Google Maps Location
https://www.google.com/maps/dir/?api=1&origin=42.040062748634,-88.086542269404&destination=United+Structural+Systems+of+Illinois%2C+2124+Stonington+Ave%2C+Hoffman+Estates%2C+IL+60169%2C+USA&destination_place_id=ChIJ-wSxDtinD4gRiv4kY3RRh9U&travelmode=driving&query=Foundation+Repair+Service
Click below to open this location on Google Maps
Google Maps Location
https://www.google.com/maps/dir/?api=1&origin=42.094120345143,-88.117899390338&destination=United+Structural+Systems+of+Illinois%2C+2124+Stonington+Ave%2C+Hoffman+Estates%2C+IL+60169%2C+USA&destination_place_id=ChIJ-wSxDtinD4gRiv4kY3RRh9U&travelmode=driving&query=carbon+fiber+wall+reinforcement
Click below to open this location on Google Maps
Google Maps Location
https://www.google.com/maps/dir/?api=1&origin=42.047538049027,-88.156119464192&destination=United+Structural+Systems+of+Illinois%2C+2124+Stonington+Ave%2C+Hoffman+Estates%2C+IL+60169%2C+USA&destination_place_id=ChIJ-wSxDtinD4gRiv4kY3RRh9U&travelmode=driving&query=Structural+Foundation+Repair
Click below to open this location on Google Maps
Google Maps Location
https://www.google.com/maps/dir/?api=1&origin=42.092599351612,-88.103413988163&destination=United+Structural+Systems+of+Illinois%2C+2124+Stonington+Ave%2C+Hoffman+Estates%2C+IL+60169%2C+USA&destination_place_id=ChIJ-wSxDtinD4gRiv4kY3RRh9U&travelmode=driving&query=Chicagoland+foundation+crack+repair
Click below to open this location on Google Maps
Google Maps Location
https://www.google.com/maps/dir/?api=1&origin=42.075378204097,-88.162831816366&destination=United+Structural+Systems+of+Illinois%2C+2124+Stonington+Ave%2C+Hoffman+Estates%2C+IL+60169%2C+USA&destination_place_id=ChIJ-wSxDtinD4gRiv4kY3RRh9U&travelmode=driving&query=structural+foundation+solutions
Click below to open this location on Google Maps
Google Maps Location
https://www.google.com/maps/dir/?api=1&origin=42.074377733434,-88.086262780534&destination=United+Structural+Systems+of+Illinois%2C+2124+Stonington+Ave%2C+Hoffman+Estates%2C+IL+60169%2C+USA&destination_place_id=ChIJ-wSxDtinD4gRiv4kY3RRh9U&travelmode=driving&query=foundation+settlement+repair
Click below to open this location on Google Maps
Google Maps Location
https://www.google.com/maps/dir/?api=1&origin=42.045957978833,-88.158387263017&destination=United+Structural+Systems+of+Illinois%2C+2124+Stonington+Ave%2C+Hoffman+Estates%2C+IL+60169%2C+USA&destination_place_id=ChIJ-wSxDtinD4gRiv4kY3RRh9U&travelmode=driving&query=residential+waterproofing+services
Click below to open this location on Google Maps
Google Maps Location
https://www.google.com/maps/dir/?api=1&origin=42.054592176062,-88.20960373186&destination=United+Structural+Systems+of+Illinois%2C+2124+Stonington+Ave%2C+Hoffman+Estates%2C+IL+60169%2C+USA&destination_place_id=ChIJ-wSxDtinD4gRiv4kY3RRh9U&travelmode=driving&query=cracked+foundation+repair
Click below to open this location on Google Maps