Related Research Articles
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.
The Modified Mercalli intensity scale measures the effects of an earthquake at a given location. This is in contrast with the seismic magnitude usually reported for an earthquake.
Seismology is the scientific study of earthquakes and the generation and propagation of elastic waves through the Earth or other planetary bodies. It also includes studies of earthquake environmental effects such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, glacial, fluvial, oceanic microseism, atmospheric, and artificial processes such as explosions and human activities. A related field that uses geology to infer information regarding past earthquakes is paleoseismology. A recording of Earth motion as a function of time, created by a seismograph is called a seismogram. A seismologist is a scientist works in basic or applied seismology.
Landslides, also known as landslips, or rockslides, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, mudflows, shallow or deep-seated slope failures and debris flows. Landslides occur in a variety of environments, characterized by either steep or gentle slope gradients, from mountain ranges to coastal cliffs or even underwater, in which case they are called submarine landslides.
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, and particularly "the determination of parameters for the next strong earthquake to occur in a region". Earthquake prediction is sometimes distinguished from earthquake forecasting, which can be defined as the probabilistic assessment of general earthquake hazard, including the frequency and magnitude of damaging earthquakes in a given area over years or decades. Not all scientists distinguish "prediction" and "forecast", but the distinction is useful.
The New Madrid Seismic Zone (NMSZ), sometimes called the New Madrid Fault Line, is a major seismic zone and a prolific source of intraplate earthquakes in the Southern and Midwestern United States, stretching to the southwest from New Madrid, Missouri.
The Hope Slide was a landslide that occurred in the morning hours of January 9, 1965 in the Nicolum Valley in the Cascade Mountains near Hope, British Columbia and killed four people. The volume of rock involved in the landslide has been estimated at 47 million cubic metres. It is one of the two largest recorded landslides in Canada.
David Alexander Johnston was an American United States Geological Survey (USGS) volcanologist who was killed by the 1980 eruption of Mount St. Helens in the U.S. state of Washington. A principal scientist on the USGS monitoring team, Johnston was killed in the eruption while manning an observation post six miles (10 km) away on the morning of May 18, 1980. He was the first to report the eruption, transmitting "Vancouver! Vancouver! This is it!" before he was swept away by a lateral blast; despite a thorough search, Johnston's body was never found, but state highway workers discovered remnants of his USGS trailer in 1993.
The Hilina Slump, on the south flank of the Kīlauea Volcano on the southeast coast of the Big Island of Hawaiʻi, is the most notable of several landslides that ring each of the Hawaiian Islands. These landslides are the means by which material deposited at a volcano's vents are transferred downward and seaward, eventually spilling onto the seabed to broaden the island.
Bruce Bolt was an Australian-born American seismologist and a professor of earth and planetary science at the University of California, Berkeley. Professor Bolt was known as a pioneer of seismic engineering. He served for 15 years on the California Seismic Safety Commission leading public debate on earthquake safety in that state, and acted as a consultant on major projects throughout the world. As well, Bolt published a number of popular and technical books on seismology.
A mudflow, also known as mudslide or mud flow, is a form of mass wasting involving fast-moving flow of debris and dirt that has become liquified by the addition of water. Such flows can move at speeds ranging from 3 meters/minute to 5 meters/second. Mudflows contain a significant proportion of clay, which makes them more fluid than debris flows, allowing them to travel farther and across lower slope angles. Both types of flow are generally mixtures of particles with a wide range of sizes, which typically become sorted by size upon deposition.
On February 17, 2006, a massive rock slide-debris avalanche occurred in the Philippine province of Southern Leyte, causing widespread damage and loss of life. The deadly landslide followed a 10-day period of heavy rain and a minor earthquake. The official death toll was 1,126.
There have been known various classifications of landslides. Broad definitions include forms of mass movement that narrower definitions exclude. For example, the McGraw-Hill Encyclopedia of Science and Technology distinguishes the following types of landslides:
Earthquake forecasting is a branch of the science of seismology concerned with the probabilistic assessment of general earthquake seismic hazard, including the frequency and magnitude of damaging earthquakes in a given area over years or decades. While forecasting is usually considered to be a type of prediction, earthquake forecasting is often differentiated from earthquake prediction, Earthquake forecasting estimates the likelihood of earthquakes in a specific timeframe and region, while earthquake prediction attempts to pinpoint the exact time, location, and magnitude of an impending quake, which is currently not reliably achievable.Wood & Gutenberg (1935). Kagan says: "This definition has several defects which contribute to confusion and difficulty in prediction research." In addition to specification of time, location, and magnitude, Allen suggested three other requirements: 4) indication of the author's confidence in the prediction, 5) the chance of an earthquake occurring anyway as a random event, and 6) publication in a form that gives failures the same visibility as successes. Kagan & Knopoff define prediction "to be a formal rule where by the available space-time-seismic moment manifold of earthquake occurrence is significantly contracted ...."</ref> Both forecasting and prediction of earthquakes are distinguished from earthquake warning systems, which, upon detection of an earthquake, provide a real-time warning to regions that might be affected.
Seismites are sedimentary beds and structures deformed by seismic shaking. The German paleontologist Adolf Seilacher first used the term in 1969 to describe earthquake-deformed layers. Today, the term is applied to both sedimentary layers and soft sediment deformation structures formed by shaking. This subtle change in usage accommodates structures that may not remain within a layer.
Boris Mavashev is an Israeli seismologist, doctor of geology and ecology, specializing in the geochemical and meteorological precursors of earthquakes.
Barry Voight is an American geologist, volcanologist, author, and engineer. After earning his Ph.D. at Columbia University, Voight worked as a professor of geology at several universities, including Pennsylvania State University, where he taught from 1964 until his retirement in 2005. He remains an emeritus professor there and still conducts research, focusing on rock mechanics, plate tectonics, disaster prevention, and geotechnical engineering.
References
- 1 2 3 "Memorial to David J. Varnes" (PDF). GSAM Memorials, v. 32. Geological Society of America. 2002. Retrieved 21 April 2024.
- 1 2 3 "David Joseph Varnes, 1919-2002". The Geological Society (UK). 2003. Retrieved 21 April 2024.
- ↑ Novotny, Jan (2013). "Varnes Landslide Classification (1978)" . Retrieved 21 April 2024.
- ↑ Varnes, David J.; Scott, Glenn R. (1970). "General and Engineering Geology of the United States Air Force Academy Site, Colorado" (PDF). Geological Survey Professional Paper 551. Retrieved 21 April 2024.
- ↑ "Landslides and Engineering Practice". 1958. Retrieved 21 April 2024.
- ↑ Varnes D. J., Slope movement types and processes. In: Schuster R. L. & Krizek R. J. Ed., Landslides, analysis and control. Transportation Research Board Sp. Rep. No. 176, Nat. Acad. oi Sciences, pp. 11–33, 1978.
- ↑ Cruden, David M.; Varnes, David J. (1996). "Landslide Types and Processes". Transportation Research Board, U.S. National Academy of Sciences, Special Report. 247: 36–75. Retrieved 21 April 2024.
- ↑ Varnes, David J.; Bufe, Charles G. (1996). "The cyclic and fractal seismic series preceding an mb 4.8 earthquake on 1980 February 14 near the Virgin Islands". Geophysical Journal International. 124 (1): 149–158. Bibcode:1996GeoJI.124..149V. doi: 10.1111/j.1365-246X.1996.tb06359.x . Retrieved 21 April 2024.
- ↑ "2004 Recipient of the Varnes Medal". Landslides. 2 (1). Springer Link: 75–77. 2005. doi:10.1007/s10346-005-0047-3 . Retrieved 21 April 2024.
| Overviews |  | |
|---|---|---|
| History of geology | ||
| Composition and structure | ||
| Historical geology | ||
| Dynamic Earth | ||
| Water | ||
| Geodesy | ||
| Geophysics | ||
| Applications | ||
| Occupations | ||
| International | |
|---|---|
| National | |
| Other | |
