A total of 36 earthquakes worldwide are included, the new database having about the same number. This paper traces thehistorical development of knowledge derived from these investigations. But scientists are wondering whether the findings could also shed light on the triggering of fast. Why do earthquakes trigger catastrophic landslides. As keefer points out, many landslides occur without seismic triggering, and therefore on a slope that is imminently unstable, a landslide could be caused by very weak shaking. The main goal of the classification of earthquaketriggered landslide events is to help improve. Earthquake ground motion and patterns of seismical. Apr 16, 2016 check out our channel for hundreds more japan videos. Study of a sample of 40 historical earthquakes shows that 14 types of landslides are caused by seismic events. Earthquakes are a major cause of landslides, which, in turn, are a major cause of the damage and casualties associated with earthquakes. Bulletin of the geological society of america 95, 406421 varnes d. Investigating landslides caused by earthquakes a historical.
Earthquakeinduced landslides geotechnical photo album. Earthquake ground motion and patterns of seismically induced. Keefer 1984, 2002 described typical characteristics of various types of earthquaketriggered landslides and their source areas. Sensitive instruments installed on and near the slowmoving landslide in maca, peru, have allowed scientists to observe the response of the landslide to earthquakes. Seismic loading is one of the main triggers of large landslides keefer, 1984. An earthquake can cause a slope to become unstable by the inertial loading it imposes or by causing a loss of strength in the slope materials. Landslides have been a product of 40 of 56 documented earthquakes in present times around the world keefer, 1984. In our flybys, the landslides begin just south from cape campbell, becoming more intense south of the clarence river, with several large 100,000 500,000 m3 landslides disrupting both state highway 1 and south island main trunk railway e. Buy landslides caused by earthquakes by david k keefer isbn. Evaluation of factors controlling earthquakeinduced.
The two blocks on a fault do not wait for an earthquake to be moved, it moves constantly without fault movement. The capability of an earthquake to trigger a landslide is a function of. A model developed by researchers at indiana university can help experts estimate the likelihood of landslides that will be caused by earthquakes anywhere in the world. Landslides caused by the klamath falls, oregon, earthquakes. Stress will build up until rocks cannot handle it and the blocks will spring back into place producing an earthquake. Analysis of a spatial distribution of landslides triggered by the 2004 chuetsu earthquakes of niigata prefecture, japan. Area affected by landslides vs earthquake magnitude. A more comprehensive definition which helps to distinguish landslides from the other geomorphological processes is the downward or outward movement of a mass of slopeforming material under the influence of gravity, occurring on. When earthquakes occur on areas with steep slopes, many times the soil slips causing landslides. The causes of landslides are usually related to instabilities in slopes. Licensed to youtube by merlin sc distribution on behalf of jagjaguwar. Earthquakes hav lone g been recognize as a d major caus oe f landslides earthquake induce. May 17, 2017 landslides are a type of natural disaster that can be triggered by earthquakes, and these slides occur along destabilized slope areas.
Keefer 1984 was the first to establish general seismic trigger thresholds. The difference between these two concepts is subtle but important. In recent years, researchers have analyzed the topography and geology, as well as the conditions related to seismic motion, in several areas where earthquakeinduced landslides have occured e. Massive utah landslide triggered earthquakes live science. Supplementary data 8411 from the gsa documents secretary. Earthquake ground motion and patterns of seismically induced landsliding. Living with earthquakes in the pacific northwest yeats. Landslides are a type of natural disaster that can be triggered by earthquakes, and these slides occur along destabilized slope areas. Landlsides triggered by earthquakes in california earthquakes are one of the main triggers that cause landslides. He has received several awards and recognitions and has written numerous scientific articles.
To quantify this association, we combine our landslide distribution with an empirical relationship proposed by keefer 4 relating the total volume of landslides generated by an earthquake and the. Jul 24, 2018 a model developed by researchers at indiana university can help experts address such risks by estimating the likelihood of landslides that will be caused by earthquakes anywhere in the world. Before 1783, historical accounts of the occurrence of landslides in earthquakes are typically so incomplete and. Beginning in 1984, syntheses of worldwide and national data on earthquakeinduced landslides have defined their general characteristics and relations between their occurrence and various geologic and seismic parameters. Earthquake induced landslides have been documented from as early as 372 bc keefer, 1984 and have caused tens of thousands of deaths and billions in economic losses keefer, 1984. Such landslides are driven by inertial forces acting on slopes and can vary in size from individual rock blocks of a few m 3 in volume to catastrophic rock avalanches of many mm 3, which can claim many thousands of lives. Impact of landslides and innovative landslidemitigation. Bulletin of the geological society of america 1984.
Read estimating losses from future earthquakes at nap. Area affected by landslides vs earthquake magnitude 2008 wenchuan earthquake, china 1999 chichi earthquake, taiwan after keefer 1984 and others, updated with recent events 2005 kashmir earthquake, pakistan and india. More than half of landslides were in some way associated with road construction and human activity table 2. The greatest losses of human life were due to rock avalanches, rapid soil flows, and rock falls. Geological society of america bulletin, 95, 406 421. Earthquake induced landslides in the himalayan mountains. Data from 40 historical worldwide earthquakes were studied to determine the characteristics, geologic environments, and hazards of landslides caused by seismic events.
A 2020 view of geologic excursions in southern california. Previous studies of worldwide earthquakes indicated that landslides occurred no farther than 36 miles from the epicenter of a magnitude 5. Overview of catastrophic landslides of south america in the. Landslides triggered by earthquakes in the central. Several studies have identified characteristics of coseismic landslides, particularly those caused by largescale earthquakes keefer 1984. Predicting earthquakeinduced landslides, with emphasis on arid and semiarid environments. Slope material that becomes saturated with water may develop a debris flow or mud flow. This sample of 40 events was supplemented with intensity data from several hundred united states earthquakes to study relations between landslide distribution and seismic. He also showed that the minimum earthquake magnitude to cause landslides is m l 4. Landslides and landslide dams caused by the kaikoura earthquake. A database of earthquakeinduced landslides has been compiled which extends the work of keefer keefer dk. Oct 18, 2014 b indirect effects influence of landslides in dam safety failure of the slopes bordering the reservoir, flooding caused by movements of large masses of soil into the reservoir. The working party on world landslide inventory 1990 defines a landslide simply as the movement of a mass of rock, earth, or debris down a slope q.
Pdf characteristics of seismically induced landslides in. Most of the landslides were rock falls or shallow, highly disrupted rock slides from roadcuts, quarries, and steep bluff. Landslides triggered by earthquakes and their relations with faults. Iu researchers develop model for predicting landslides caused. Coseismic landslides are important effects of strong earthquakes and one of the most poorly understood. The ongoing collision between the indian and eurasian plates that has generated the himalayas occurs along a huge set of faults that run through the frontal. Postearthquake field investigations of landslide occurrence have provided a basis for. Landslides triggered by earthquakes in the central mississippi. Similarly, amongst the earthquakes in the database of rodrguez et al. Nov 30, 2016 earthquake induced landslides in the himalayan mountains new evidence for earthquake potential in bhutan in terms of large earthquakes bhutan has always been something of a conundrum. What makes this new study so unique is that it provides direct observational evidence from the largest earthquake to occur in more than 100 years in the eastern u.
The 1984 otaki earthquake hit nagano prefecture, japan on september 14, 1984, at 08. Keefer 1984 summarized past records to classify them and also to show the maximum distance to landslides for varying seismic magnitudes. Landslides and flooding debris flow can cause flooding by blocking valleys and stream channels, forcing large amounts of water to backup causing backup flash flood. A new classification of earthquakeinduced landslide event sizes. Landslides caused by earthquakes gsa bulletin geoscienceworld. Earthquakes, landslides and tsunamis li juan and chen yong encyclopedia of life support systems eolss magnitude m5. Shaking from chiles earthquake was felt even in peru and bolivia. Natural hazards, early warning of coastal earthquakes, soil moisture, landslides, snow avalanches, floods, dust storms, remote sensing applications, geophysical explorations, atmospheric pollution and mining environment. For sale by the books and openfile reports section, u. The magnitude is used in seismology to represent the seismic moment that measures the energy released by an earthquake. Landslides, earthquakes, and erosion sciencedirect. The additional use of geographic information system gis processing and digital mapping since about 1989 has greatly facilitated the level of analysis that can applied to mapped distributions of landslides.
Models of the triggering of landslides during earthquakes. Geological survey, denver, colorado on march 5, 1987, two earthquakes m s 6. R geological survey, 345 middlefield road, ms 998, menlo park, california 94025 abstract data fro 4m0 historica worldwidl earthe quakes were studied t o determine th e characteristics, geologi environmentsc an hazardd, of s landslides caused by seismic events. Bulletin of the seismological society of america, 95, pp. Everyday low prices and free delivery on eligible orders.
The most abundant of these were rock falls, disrupted soil slides, and rock slides. Postearthquake field investigations of landslide occurrence have provided a basis for understanding, evaluating, and mapping the hazard and risk associated withearthquakeinduced landslides. Earthquakeinduced landslides earthquake shaking can cause landsliding on many scales, as some of these examples show. In a study of 40 major historic earthquakes, keefer 1984 has shown that landslides can be triggered over an area as large as 500,000 km 2 by a m9. Each type of earthquakeinduced landslide occurs in a particular suite of. Beginning in 1984, synthesis of worldwide and national data on earthquakeinduced landslides have defined their general characteristics. In his report of a field investigation of the new madrid earthquakes con ducted in 1904, fuller 1912, p. Earthquake ground motion and patterns of seismically.
The more energy an earthquake has released, the higher its magnitude. On may 22, 1960, one of the worlds strongest historic earthquakes m w 9. The resulting slurry of rock and mud may pick up trees, houses, and cars, thus blocking. For example, overall only large earthquakes typically m w. Materials most susceptible to earthquakeinduced landslides include weakly cemented rocks, moreindurated rocks. The klamath falls earthquakes caused landslides throughout an area of about 420 sq km and as far as about 29 km from the epicenter, a distribution that is typical for magnitude 6 earthquakes see graphs on following pages. Damage caused by earthquake landslides authorstream. When sloped areas become completely saturated by heavy rainfall many times landslides can occur.