Tomographic evidence for hydrated oceanic crust of the Pacific slab
... crust become unstable with increasing pressure and temperature, and consequently dehydration reactions occur accompanied by the release of water to the surroundings. Hydrated oceanic crust, which is expected to be lower seismic velocity compared to the surrounding mantle, has been detected in variou ...
... crust become unstable with increasing pressure and temperature, and consequently dehydration reactions occur accompanied by the release of water to the surroundings. Hydrated oceanic crust, which is expected to be lower seismic velocity compared to the surrounding mantle, has been detected in variou ...
Deep crustal fracture zones control fluid escape and the seismic
... ior is segmented along the Cascadia margin. Aseismic slip events, non-volcanic tremors, and low-frequency earthquakes, are also the manifestation of the short-term frictional behavior on the subduction megathrust (Dragert et al., 2001; Rogers and Dragert, 2003; Shelly et al., 2006). Along-strike var ...
... ior is segmented along the Cascadia margin. Aseismic slip events, non-volcanic tremors, and low-frequency earthquakes, are also the manifestation of the short-term frictional behavior on the subduction megathrust (Dragert et al., 2001; Rogers and Dragert, 2003; Shelly et al., 2006). Along-strike var ...
A Three-Dimensional Model of the Lithosphere Dynamics
... thereby attracts the attention of both scientists and statesmen. This region is characterized by a very high geodynamic and seismic activity, which makes it seismically hazardous. The strongest earthquakes with magnitudes of 8.0 and higher are known to have occurred on the southern, western, and eas ...
... thereby attracts the attention of both scientists and statesmen. This region is characterized by a very high geodynamic and seismic activity, which makes it seismically hazardous. The strongest earthquakes with magnitudes of 8.0 and higher are known to have occurred on the southern, western, and eas ...
Review of Seismic Retrofitting Strategies for Residential Buildings in
... by gas extraction, the Dutch government decided to cut output from the gas field as well as upgrade existing houses in this region. Due to the fact, that it is expected, that the frequency as well as magnitude of these earthquakes will rise, the development of structural upgrading strategies plays a ...
... by gas extraction, the Dutch government decided to cut output from the gas field as well as upgrade existing houses in this region. Due to the fact, that it is expected, that the frequency as well as magnitude of these earthquakes will rise, the development of structural upgrading strategies plays a ...
Structures
... Shear zone - zone of deformed rocks that are more highly strained than surrounding rocks • common in mid- to lower levels of crust ...
... Shear zone - zone of deformed rocks that are more highly strained than surrounding rocks • common in mid- to lower levels of crust ...
application of micro-seismic methods to geothermal exploration
... laid in a network to determine the locations and nature of the earthquakes within a given prospect area as shown in the Menengai Volcanic area [Figure 2.2]. A wider area network can also be deployed centred on the main prospect of interest with raypaths expected to cross the volcanic centres. The wi ...
... laid in a network to determine the locations and nature of the earthquakes within a given prospect area as shown in the Menengai Volcanic area [Figure 2.2]. A wider area network can also be deployed centred on the main prospect of interest with raypaths expected to cross the volcanic centres. The wi ...
Earth`s Crust Test Prep
... Oregon may allow the tracking of a volcanic eruption from its beginning, long before the smoke and explosions begin. This uplift is most likely caused by an upflow of molten rock from more than four miles below the surface. Rock melts within Earth’s interior and then moves upward in cracks in Earth’ ...
... Oregon may allow the tracking of a volcanic eruption from its beginning, long before the smoke and explosions begin. This uplift is most likely caused by an upflow of molten rock from more than four miles below the surface. Rock melts within Earth’s interior and then moves upward in cracks in Earth’ ...
A fault caught in the act of burping
... Island Block 330 field, where anomalously high pore pressures have been reported in the fault zone (Anderson et al., 1995; Losh et al., 1999), areas of high reflectivity appear to move up the fault-plane, as would be expected for an ascending, pressure-driven fluid pulse. The seismic waves are able ...
... Island Block 330 field, where anomalously high pore pressures have been reported in the fault zone (Anderson et al., 1995; Losh et al., 1999), areas of high reflectivity appear to move up the fault-plane, as would be expected for an ascending, pressure-driven fluid pulse. The seismic waves are able ...
FROM PHONONIC CRYSTALS TO SEISMIC METAMATERIALS
... where the velocity of the wave is decreasing, since the higher frequency components are more effectively attenuated during wave propagation. The fact that these surface waves have a slower speed, hence a much smaller wavelength than underground waves, makes them the most destructive seismic waves an ...
... where the velocity of the wave is decreasing, since the higher frequency components are more effectively attenuated during wave propagation. The fact that these surface waves have a slower speed, hence a much smaller wavelength than underground waves, makes them the most destructive seismic waves an ...
Postseismic crustal deformation following the
... and the Hokkaido Nansei-oki earthquake occurred between the focal regions of the 1940 Shakotan earthquake (M = 7.5) to the north and the 1983 Japan Sea earthquake (M = 7.7) to the south. Kobayashi [1983] and Nakamura [1983] proposed that a nascent trench (the dashed line in Figure 1) is present alon ...
... and the Hokkaido Nansei-oki earthquake occurred between the focal regions of the 1940 Shakotan earthquake (M = 7.5) to the north and the 1983 Japan Sea earthquake (M = 7.7) to the south. Kobayashi [1983] and Nakamura [1983] proposed that a nascent trench (the dashed line in Figure 1) is present alon ...
Principle of Equivalence
... strain to longitudinal extension strain in the direction of stretching force. Tensile deformation is considered positive and compressive deformation is considered negative. The definition of Poisson's ratio contains a minus sign so that normal materials have a positive ratio ...
... strain to longitudinal extension strain in the direction of stretching force. Tensile deformation is considered positive and compressive deformation is considered negative. The definition of Poisson's ratio contains a minus sign so that normal materials have a positive ratio ...
The Armenian earthquake of 1988 December 7: faulting and folding
... series of structures is NNW-SSE to N-S. Nevertheless, local irregularities are observed, showing that the fault is complex at the surface. Ruptures are discontinuous and localized within a 1km wide band in the central part. Conjugate subsegments increase the complexity. Vertical slip is important on ...
... series of structures is NNW-SSE to N-S. Nevertheless, local irregularities are observed, showing that the fault is complex at the surface. Ruptures are discontinuous and localized within a 1km wide band in the central part. Conjugate subsegments increase the complexity. Vertical slip is important on ...
Geometrical impact of the San Andreas Fault on stress and
... 2005], and run the model on a 16-nodes PC cluster. [7] The eastern side of the model domain is fixed, while the western side is loaded by a shear velocity of 49 mm/yr representing relative motion between the Pacific and the North American plates. Stress evolution is calculated at tenyear time steps. ...
... 2005], and run the model on a 16-nodes PC cluster. [7] The eastern side of the model domain is fixed, while the western side is loaded by a shear velocity of 49 mm/yr representing relative motion between the Pacific and the North American plates. Stress evolution is calculated at tenyear time steps. ...
Distributed deformation in the lower crust and upper mantle beneath
... assign anisotropy to a preferred orientation of mineral grains (Godfrey et al., 2000). Although the relationship between crustal strain and seismic fast and slow axes remains controversial, the presence and cause of seismic anisotropy are not. Seismic anisotropy of the lower crust in a zone .;60 km ...
... assign anisotropy to a preferred orientation of mineral grains (Godfrey et al., 2000). Although the relationship between crustal strain and seismic fast and slow axes remains controversial, the presence and cause of seismic anisotropy are not. Seismic anisotropy of the lower crust in a zone .;60 km ...
Crustal structure and local seismicity in western Anatolia
... the linear array of about 100 km. The instruments lay in that configuration for the remaining months of recording. The linear array traversed two prominent E–W trending grabens in western Turkey: the Buyuk Menderes and the Kucuk Menderes Graben (KMG). Four high-frequency and five broad-band instrume ...
... the linear array of about 100 km. The instruments lay in that configuration for the remaining months of recording. The linear array traversed two prominent E–W trending grabens in western Turkey: the Buyuk Menderes and the Kucuk Menderes Graben (KMG). Four high-frequency and five broad-band instrume ...
Imaging the Gutenberg Seismic Discontinuity beneath the Oceanic
... SS precursor data, I collected a seismic dataset that consisted of earthquakes that sampled beneath the North American oceanic crust. To look for data that would be compatible with this project, several criteria had to be outlined. For example, I only used earthquake events that occurred shallower t ...
... SS precursor data, I collected a seismic dataset that consisted of earthquakes that sampled beneath the North American oceanic crust. To look for data that would be compatible with this project, several criteria had to be outlined. For example, I only used earthquake events that occurred shallower t ...
Faulting and hydration of the Juan de Fuca plate system
... largely restricted to crustal levels. If dehydration embrittlement is an important mechanism for triggering intermediate-depth earthquakes within the subducting slab, then the limited occurrence rate and magnitude of intraslab seismicity at the Cascadia margin may in part be explained by the limited ...
... largely restricted to crustal levels. If dehydration embrittlement is an important mechanism for triggering intermediate-depth earthquakes within the subducting slab, then the limited occurrence rate and magnitude of intraslab seismicity at the Cascadia margin may in part be explained by the limited ...
Where and why do large shallow slab earthquakes occur?
... (1997) inferred that this event occurred within the Philippine Sea slab at the 40-50 km depth, based on the fact that severe damage was localized at the epicenter, but strong shaking was felt in a wide area, which is a characteristic feature to the slab events in this area. The 1905 Geiyo earthquake ...
... (1997) inferred that this event occurred within the Philippine Sea slab at the 40-50 km depth, based on the fact that severe damage was localized at the epicenter, but strong shaking was felt in a wide area, which is a characteristic feature to the slab events in this area. The 1905 Geiyo earthquake ...
B. A. Part-I Geography Title english.pmd
... Except above mentioned features rock formation structure, distribution and minerals also studies in this discipline. This study is useful for understanding the internal processes. First and important stape at studding physical factors of earth is observation. The information about structure, texture ...
... Except above mentioned features rock formation structure, distribution and minerals also studies in this discipline. This study is useful for understanding the internal processes. First and important stape at studding physical factors of earth is observation. The information about structure, texture ...
Seismic Response of High Plasticity Clays subjected
... 1985 Michoacan earthquake. This paper presents the study of the seismic response of typical high plasticity clays found in the so-called Texcoco Lake, in the surrounding of Mexico City valley, for larger to extreme events. An instrumented soft soil site was used in the study. The shear wave velocity ...
... 1985 Michoacan earthquake. This paper presents the study of the seismic response of typical high plasticity clays found in the so-called Texcoco Lake, in the surrounding of Mexico City valley, for larger to extreme events. An instrumented soft soil site was used in the study. The shear wave velocity ...
SoE2 Geological changes earth`s structure
... Most earthquakes occur at plate boundaries where stress has accumulated over time. When stress is released in faulting, the rocks rebound elastically to produce P, S and surface, (L) waves. Since these travel with different velocities, they can be detected in turn by seismometers that are far enough ...
... Most earthquakes occur at plate boundaries where stress has accumulated over time. When stress is released in faulting, the rocks rebound elastically to produce P, S and surface, (L) waves. Since these travel with different velocities, they can be detected in turn by seismometers that are far enough ...
Section 4: Forsyth Barr building - Canterbury Earthquakes Royal
... The shaking was mainly in the east–west direction, with a significant vertical component. It was of a short duration, but had high accelerations and displacements because its epicentre was close to the CBD. When the earthquake struck, the Forsyth Barr building was evidently subjected to strong accel ...
... The shaking was mainly in the east–west direction, with a significant vertical component. It was of a short duration, but had high accelerations and displacements because its epicentre was close to the CBD. When the earthquake struck, the Forsyth Barr building was evidently subjected to strong accel ...
P-Waves and S-Waves
... through the earth. These seismic waves are recorded -graph something that writes by a seismometer. or records Ask students to sit across from each other at a table, -gram something written or ask them to move their desks so that they are ardown, drawn or recorded ranged in pairs, facing one anothe ...
... through the earth. These seismic waves are recorded -graph something that writes by a seismometer. or records Ask students to sit across from each other at a table, -gram something written or ask them to move their desks so that they are ardown, drawn or recorded ranged in pairs, facing one anothe ...
The recent seismo-volcanic activity at Deception Island volcano
... have been located on linear faults, some of which lie outside the hypothetical ring fault, while others cut the caldera. One implication of their model is that the caldera may be underlain by much less extensive and perhaps discontinuous magma reservoirs whose position is controlled by the location ...
... have been located on linear faults, some of which lie outside the hypothetical ring fault, while others cut the caldera. One implication of their model is that the caldera may be underlain by much less extensive and perhaps discontinuous magma reservoirs whose position is controlled by the location ...
- Wiley Online Library
... arrays, which locate seismically generated acoustic phases, known as tertiary (T) waves [e.g., Fox et al., 1994, 2001]. In these studies, the size of an earthquake is represented in terms of its acoustic source level (dB re 1 mPa @ 1m). Source levelfrequency distributions also exhibit a power law be ...
... arrays, which locate seismically generated acoustic phases, known as tertiary (T) waves [e.g., Fox et al., 1994, 2001]. In these studies, the size of an earthquake is represented in terms of its acoustic source level (dB re 1 mPa @ 1m). Source levelfrequency distributions also exhibit a power law be ...
Earthquake
An earthquake (also known as a quake, tremor or temblor) is the perceptible shaking of the surface of the Earth, which can be violent enough to destroy major buildings and kill thousands of people. The severity of the shaking can range from barely felt to violent enough to toss people around. Earthquakes have destroyed whole cities. They result from the sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time.Earthquakes are measured using observations from seismometers. The moment magnitude is the most common scale on which earthquakes larger than approximately 5 are reported for the entire globe. The more numerous earthquakes smaller than magnitude 5 reported by national seismological observatories are measured mostly on the local magnitude scale, also referred to as the Richter magnitude scale. These two scales are numerically similar over their range of validity. Magnitude 3 or lower earthquakes are mostly almost imperceptible or weak and magnitude 7 and over potentially cause serious damage over larger areas, depending on their depth. The largest earthquakes in historic times have been of magnitude slightly over 9, although there is no limit to the possible magnitude. The most recent large earthquake of magnitude 9.0 or larger was a 9.0 magnitude earthquake in Japan in 2011 (as of March 2014), and it was the largest Japanese earthquake since records began. Intensity of shaking is measured on the modified Mercalli scale. The shallower an earthquake, the more damage to structures it causes, all else being equal.At the Earth's surface, earthquakes manifest themselves by shaking and sometimes displacement of the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides, and occasionally volcanic activity.In its most general sense, the word earthquake is used to describe any seismic event — whether natural or caused by humans — that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults, but also by other events such as volcanic activity, landslides, mine blasts, and nuclear tests. An earthquake's point of initial rupture is called its focus or hypocenter. The epicenter is the point at ground level directly above the hypocenter.