Upper mantle deformation beneath the North American–Pacific plate
... is well linearized after anisotropy correction [see Wüstefeld et al., 2008]. Fair measurements fit at least four of these conditions; the other ones are poor measurements. This qualitative approach is very useful for analyzing and sorting the final results. Filtering was manually applied depending o ...
... is well linearized after anisotropy correction [see Wüstefeld et al., 2008]. Fair measurements fit at least four of these conditions; the other ones are poor measurements. This qualitative approach is very useful for analyzing and sorting the final results. Filtering was manually applied depending o ...
Slab pull, slab weakening, and their relation to deep intraslab
... guiding stresses within the slab [Christova and Scholz, 2003; Conrad et al., 2004]. Hence we might expect a relationship between slabs that are able to transfer stress effectively to the surface (i.e. having strong plate-slab attachment) and the frequency and magnitude of intermediate and deep focus ...
... guiding stresses within the slab [Christova and Scholz, 2003; Conrad et al., 2004]. Hence we might expect a relationship between slabs that are able to transfer stress effectively to the surface (i.e. having strong plate-slab attachment) and the frequency and magnitude of intermediate and deep focus ...
Relationship between displacement and velocity
... The author focus on the relationships among logarithmic displacement and velocity amplitudes, and magnitude in this paper. This is related to an attempt of determining a magnitude from regional velocity amplitudes. Relationship between magnitude and ground velocity has been examined to estimate peak ...
... The author focus on the relationships among logarithmic displacement and velocity amplitudes, and magnitude in this paper. This is related to an attempt of determining a magnitude from regional velocity amplitudes. Relationship between magnitude and ground velocity has been examined to estimate peak ...
Testing earthquake predictions
... geophysicists disagree about whether earthquake prediction is possible in principle.3 How, then, ought we decide whether a method for predicting earthquakes works? Earthquake predictions have been assessed using ideas from statistical hypothesis testing: A test statistic is compared to its distribut ...
... geophysicists disagree about whether earthquake prediction is possible in principle.3 How, then, ought we decide whether a method for predicting earthquakes works? Earthquake predictions have been assessed using ideas from statistical hypothesis testing: A test statistic is compared to its distribut ...
On the onset of ionospheric precursors 40 min before strong
... slant TEC. The anomaly identified by Heki [2011] is relative to a cubic least squares fit to the STEC time series (see the supporting information, description of the method, in Heki [2011]). According to Heki [2011], Mw > 8 earthquakes are preceded by similar anomalous preseismic STEC increases. The T ...
... slant TEC. The anomaly identified by Heki [2011] is relative to a cubic least squares fit to the STEC time series (see the supporting information, description of the method, in Heki [2011]). According to Heki [2011], Mw > 8 earthquakes are preceded by similar anomalous preseismic STEC increases. The T ...
NON DESTRUCTIVE TEST METHODS OF STONE AND ROCK
... path, the time difference and the damping. In the case of the steady-state method the quantities measured are the length of the travel path, the phase differences at different frequencies and possibly the attenuation at different frequencies. The equipment needed for this test method is an exciter, ...
... path, the time difference and the damping. In the case of the steady-state method the quantities measured are the length of the travel path, the phase differences at different frequencies and possibly the attenuation at different frequencies. The equipment needed for this test method is an exciter, ...
A seismic discontinuity in the upper mantle between the Eastern
... and the Moho. Structures in the upper mantle are more likely to be discovered by analyses of teleseismic data, although these methods are restricted in their resolution capabilities. The relatively rare evidence for upper mantle refractors or reflectors in active source data enables challenging and i ...
... and the Moho. Structures in the upper mantle are more likely to be discovered by analyses of teleseismic data, although these methods are restricted in their resolution capabilities. The relatively rare evidence for upper mantle refractors or reflectors in active source data enables challenging and i ...
Repeating earthquakes in the Yellowstone volcanic field
... in our dataset. We thus choose a cross-correlation value of 0.85 as a threshold to select all the earthquake pairs within the range of separation of theoretical 3.1 Hz doublets and showing significant high cross-correlation coefficients. The window length and the correlation threshold were chosen for ...
... in our dataset. We thus choose a cross-correlation value of 0.85 as a threshold to select all the earthquake pairs within the range of separation of theoretical 3.1 Hz doublets and showing significant high cross-correlation coefficients. The window length and the correlation threshold were chosen for ...
Segmentation of seismicity along the Himalayan Arc due to
... of the mid-crustal ramp under the southern Higher or northern Lesser Himalaya. The ramp connects the shallow and seismically active detachment to the south with the deeper and aseismically slipping detachment to the north. To validate whether the presence of the ramp influences the seismicity of the ...
... of the mid-crustal ramp under the southern Higher or northern Lesser Himalaya. The ramp connects the shallow and seismically active detachment to the south with the deeper and aseismically slipping detachment to the north. To validate whether the presence of the ramp influences the seismicity of the ...
Westbrook et al., (1988)
... seismic velocity. The loss of the bright reflector at 70 km could be because it is intersected by a thrust that soles out at a lower stratigraphic level and the old decollement is deformed in the hanging wall. At 58 km, a thrust cuts down into the underlying sequence without a loss of brightness on ...
... seismic velocity. The loss of the bright reflector at 70 km could be because it is intersected by a thrust that soles out at a lower stratigraphic level and the old decollement is deformed in the hanging wall. At 58 km, a thrust cuts down into the underlying sequence without a loss of brightness on ...
the effectiveness of viscous dampers for structures subjected to
... The input histories used in analysis were based on the two components of the 22 far-filed (measured 10 km or more from fault rupture) NGA PEER (2009b) records. These 44 records have been identified by ATC 63 (FEMA 2009) for collapse evaluation analysis. The selected 22 records correspond to a relati ...
... The input histories used in analysis were based on the two components of the 22 far-filed (measured 10 km or more from fault rupture) NGA PEER (2009b) records. These 44 records have been identified by ATC 63 (FEMA 2009) for collapse evaluation analysis. The selected 22 records correspond to a relati ...
Seismic retrofit
Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. With better understanding of seismic demand on structures and with our recent experiences with large earthquakes near urban centers, the need of seismic retrofitting is well acknowledged. Prior to the introduction of modern seismic codes in the late 1960s for developed countries (US, Japan etc.) and late 1970s for many other parts of the world (Turkey, China etc.), many structures were designed without adequate detailing and reinforcement for seismic protection. In view of the imminent problem, various research work has been carried out. State-of-the-art technical guidelines for seismic assessment, retrofit and rehabilitation have been published around the world - such as the ASCE-SEI 41 and the New Zealand Society for Earthquake Engineering (NZSEE)'s guidelines. These codes must be regularly updated; the 1994 Northridge earthquake brought to light the brittleness of welded steel frames, for example.The retrofit techniques outlined here are also applicable for other natural hazards such as tropical cyclones, tornadoes, and severe winds from thunderstorms. Whilst current practice of seismic retrofitting is predominantly concerned with structural improvements to reduce the seismic hazard of using the structures, it is similarly essential to reduce the hazards and losses from non-structural elements. It is also important to keep in mind that there is no such thing as an earthquake-proof structure, although seismic performance can be greatly enhanced through proper initial design or subsequent modifications.