scholarly journals Early estimate of epicenter seismic intensities according to co-seismic deformation

2010 ◽  
Vol 49 (2) ◽  
Author(s):  
Li Weidong ◽  
Zhang Chaojun ◽  
Li Dahui ◽  
He Jiayong ◽  
Chen Huizhong ◽  
...  

Para un sismo, el desplazamiento cosísmico absoluto de la falla puede calcularse con base de la localización, la profundidad focal, el mecanismo focal y la magnitud. Así, en base a informaciones provenientes de estaciones remotas, es posible estimar el desplazamiento cosísmico e inferir la correspondiente distribución de intensidades sísmicas. Se presenta el ejemplo del sismo de Wenchuan de 2008, M8.0, y se determina exitosamente la distribución de intensidades utilizando los desplazamientos cosísmicos más un modelo de velocidades. Una evaluación preliminar de intensidades es indispensable para efectos de un diagnóstico temprano del desastre y de una respuesta emergente efectiva en caso de un sismo destructor como el de 2008 en Wenchuan, China.

2019 ◽  
Vol 484 (1) ◽  
pp. 87-92
Author(s):  
T. M. Zlobina ◽  
V. A. Petrov ◽  
K. Yu. Murashov ◽  
A. A. Kotov

This study investigates the effect of mechanisms of paleode formations during the period of fluid inflow into the accumulation sphere of gold concentrations. Such mechanisms are believed to correspond to DC- and NDC- type seismic mechanisms, whose main influence on fluid migration lies on the formation of different, relative to fluid regime parameters, structural and hydrodynamic organizations of the ore-forming system, and fluid flow control within the area of the accumulation of ore concentrations.  


2021 ◽  
Author(s):  
Athanassios Ganas ◽  
Panagiotis Elias ◽  
Pierre Briole ◽  
Sotiris Valkaniotis ◽  
Javier Escartin ◽  
...  

2021 ◽  
pp. 101847
Author(s):  
Barbara Orecchio ◽  
Giancarlo Neri ◽  
Debora Presti ◽  
Silvia Scolaro ◽  
Cristina Totaro

2009 ◽  
Vol 03 (02) ◽  
pp. 77-88 ◽  
Author(s):  
HASANUDDIN Z. ABIDIN ◽  
HERI ANDREAS ◽  
TERUYUKI KATO ◽  
TAKEO ITO ◽  
IRWAN MEILANO ◽  
...  

Along the Java trench the Australian–Oceanic plate is moving and pushing onto and subducting beneath the Java continental crust at a relative motion of about 70 mm/yr in NNE direction. This subduction-zone process imposed tectonic stresses on the fore-arc region offshore and on the land of Java, thus causing the formation of earthquake fault zones to accommodate the plate movement. Historically, several large earthquakes happened in Java, including West Java. This research use GPS surveys method to study the inter-seismic deformation of three active faults in West Java region (i.e. Cimandiri, Lembang and Baribis faults), and the co-seismic and post-seismic deformation related to the May 2006 Yogyakarta and the July 2006 South Java earthquakes. Based on GPS surveys results it was found that the area around Cimandiri, Lembang and Baribis fault zones have the horizontal displacements of about 1 to 2 cm/yr or less. Further research is however still needed to extract the real inter-seismic deformation of the faults from those GPS-derived displacements. GPS surveys have also estimated that the May 2006 Yogyakarta earthquake was caused by the sinistral movement of the (Opak) fault with horizontal co-seismic deformation that generally was less than 10 cm. The post-seismic horizontal deformation of the July 2006 South Java tsunami earthquake has also been estimated using GPS surveys data. In the first year after the earthquake (2006 to 2007), the post-seismic deformation is generally less than 5 cm; and it becomes generally less than 3 cm in the second year (2007 to 2008).


2021 ◽  
Vol 11 (11) ◽  
pp. 4817
Author(s):  
Filippos Vallianatos ◽  
Vassilis Sakkas

In the present work, a multiscale post-seismic relaxation mechanism, based on the existence of a distribution in relaxation time, is presented. Assuming an Arrhenius dependence of the relaxation time with uniform distributed activation energy in a mesoscopic scale, a generic logarithmic-type relaxation in a macroscopic scale results. The model was applied in the case of the strong 2015 Lefkas Mw6.5 (W. Greece) earthquake, where continuous GNSS (cGNSS) time series were recorded in a station located in the near vicinity of the epicentral area. The application of the present approach to the Lefkas event fits the observed displacements implied by a distribution of relaxation times in the range τmin ≈3.5 days to τmax ≈350 days.


2021 ◽  
pp. M56-2021-22
Author(s):  
Mirko Scheinert ◽  
Olga Engels ◽  
Ernst J. O. Schrama ◽  
Wouter van der Wal ◽  
Martin Horwath

AbstractGeodynamic processes in Antarctica such as glacial isostatic adjustment (GIA) and post-seismic deformation are measured by geodetic observations such as GNSS and satellite gravimetry. GNSS measurements have been comprising continuous measurements as well as episodic measurements since the mid-1990s. The estimated velocities typically reach an accuracy of 1 mm/a for horizontal and 2 mm/a for vertical velocities. However, the elastic deformation due to present-day ice-load change needs to be considered accordingly.Space gravimetry derives mass changes from small variations in the inter-satellite distance of a pair of satellites, starting with the GRACE satellite mission in 2002 and continuing with the GRACE-FO mission launched in 2018. The spatial resolution of the measurements is low (about 300 km) but the measurement error is homogeneous across Antarctica. The estimated trends contain signals from ice mass change, local and global GIA signal. To combine the strengths of the individual data sets statistical combinations of GNSS, GRACE and satellite altimetry data have been developed. These combinations rely on realistic error estimates and assumptions of snow density. Nevertheless, they capture signal that is missing from geodynamic forward models such as the large uplift in the Amundsen Sea sector due to low-viscous response to century-scale ice-mass changes.


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