scholarly journals Strong ground motion simulation of the 27 May 2006 Yogyakarta earthquake using Empirical Green’s Function

2021 ◽  
Vol 873 (1) ◽  
pp. 012080
Author(s):  
Yeremia Hanniel ◽  
Ade Anggraini ◽  
Agus Riyanto ◽  
Drajat Ngadmanto ◽  
Wiwit Suryanto
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Moment Tensor ◽  
Source Parameters ◽  
Maximum Amplitude ◽  
Earthquake Source ◽  
Ground Acceleration ◽  
Moment Tensor Solution ◽  
Earthquake Source Parameters ◽  
Strong Ground Motion Simulation

Abstract On May 27, 2006, 05:54 am local time, a moderate crustal earthquake of magnitude Mw 6,3 struck the Yogyakarta province, especially in the Bantul regency in the south part of the province. The earthquake damaged or destroyed more than 400,000 houses and buildings and caused more than 5,700 people killed. Several earthquake stations recorded the ground vibration caused by the mainshock very well, except at the stations closest to the earthquake source, namely YOGI in Gamping, West of Yogyakarta, which experienced saturation due to significant vibration. Therefore, information about the maximum ground acceleration near the source is yet not known. We model the ground vibrations near the earthquake source using a stochastic Green’s Function approach to obtain information about the ground motions’ maximum amplitude. The earthquake source parameters we referred to is the moment tensor solution from the Harvard Moment Tensor. The calculations show that the amplitude is consistent with observations recorded at the BJI Banjarnegara (0.04g) and YOGI Yogyakarta (0.3g).

Earthquake source parameters at the sumatran fault zone: Identification of the activated fault plane

2010 ◽  
Vol 2 (4) ◽  
Author(s):  
Madlazim Kasmolan ◽  
Bagus Santosa ◽  
Jonathan Lees ◽  
Widya Utama
Keyword(s):  
Fault Zone ◽  
Moment Tensor ◽  
Source Parameters ◽  
Earthquake Source ◽  
Joint Analysis ◽  
Seismic Fault ◽  
Earthquake Source Parameters ◽  
Sumatran Fault ◽  
Centroid Position

AbstractFifteen earthquakes (Mw 4.1–6.4) occurring at ten major segments of the Sumatran Fault Zone (SFZ) were analyzed to identify their respective fault planes. The events were relocated in order to assess hypocenter uncertainty. Earthquake source parameters were determined from three-component local waveforms recorded by IRIS-DMC and GEOFON broadband lA networks. Epicentral distances of all stations were less than 10°. Moment tensor solutions of the events were calculated, along with simultaneous determination of centroid position. Joint analysis of hypocenter position, centroid position, and nodal planes produced clear outlines of the Sumatran fault planes. The preferable seismotectonic interpretation is that the events activated the SFZ at a depth of approximately 14–210 km, corresponding to the interplate Sumatran fault boundary. The identification of this seismic fault zone is significant to the investigation of seismic hazards in the region.

Deriving centimeter-level coseismic deformations and source parameters of small-to-moderate earthquakes from time-series Sentinel-1 SAR images

2021 ◽  
Author(s):  
Heng Luo ◽  
Teng Wang ◽  
Shengji Wei ◽  
Mingsheng Liao
Keyword(s):  
Moment Tensor ◽  
Source Parameters ◽  
Deformation Gradient ◽  
Sampling Rate ◽  
Earthquake Source ◽  
Coseismic Deformation ◽  
Sar Images ◽  
Moderate Size ◽  
Trade Offs ◽  
Earthquake Source Parameters

<p>Small-to-moderate size earthquakes occur much more frequently than large ones but are general less studied by InSAR, despite that they also provide critical information about the physics of faulting and earthquake mechanisms. The weak coseismic deformations contaminated by severe atmosphere turbulences make them difficult to be studied by single interferogram. Since the launchings on April, 2014 and April, 2016, Sentinel-1 A/B satellites began to provide large-coverage SAR images in short revisited period (6 or 12 days) with 250 km frame width. The high-temporal sampling rate of Sentinel-1 data produce sufficient images for the stacking process to greatly reduce the local atmospheric turbulence that is difficult to be handled by numerical weather models. This procedure allows the extraction of very weak coseismic deformation (i.e. sub-centimeter) for small-to-moderate size earthquakes and systematical static slip inversions of the earthquakes in a tectonically active region by InSAR.</p><p> </p><p>Here we report this stacking method and a new downsampling strategy based on quadtree mesh obtained from preliminary slip model to efficiently reduce the number of unwanted data points. Applying the proposed methods, we successfully retrieve coseismic deformations for 33 earthquakes (Mw4.1-Mw6.6) occurred in west China from Nov, 2014 to Jul 2020. Among these earthquakes, the smallest peak Line-of-Sight coseismic deformation is only ~6 mm. These InSAR-based earthquake catalogs show robust and precise absolute location (latitude, longitude and depth), therefore can be used as benchmark events to calibrate seismic based catalogues. However, strong trade-offs between earthquake source parameters (e.g. fault size vs slip) exist when the earthquake magnitude is small (in general smaller than Mw5.5). Such trade-offs are rooted due to the smaller deformation gradient in comparison with larger earthquakes. For the moderate size earthquakes (Mw6.0-6.6), the comparison between equivalent moment tensor from InSAR slip models and GCMT/W-phase solutions show that large CLVD components, as shown in the seismic-based moment tensor solutions, are mostly not necessary to explain the InSAR data. We suggest to combine geodetic and seismic datasets for more comprehensive and accurate earthquake source parameter inversions.</p>

scholarly journals Modeling of earthquake source parameters on December 12, 2018 (08:49:56,16; 36,4478° N; 140,5788° E; H = 62,0 km; Mw = 4,3, Japan)

2021 ◽  
Vol 43 (4) ◽  
pp. 105-118
Author(s):  
R.M. Pak ◽  
O.D. Hrytsai
Keyword(s):  
Focal Mechanism ◽  
Seismic Moment ◽  
Matrix Method ◽  
Moment Tensor ◽  
Source Parameters ◽  
Earthquake Source ◽  
Local Network ◽  
Seismic Moment Tensor ◽  
Earthquake Source Parameters ◽  
The Matrix

Modeling of earthquake source parameters, such as the orientation of the fault plane and the direction of the fault slip, is important for understanding the physics of earthquake source processes, determining the stress-strain state of the geological medium and seismic hazard estimation. For modeling source parameters of the earthquake on December 12, 2018 at 08:49:56,16 (UTC) in Japan (36,4478° N, 140,5788° E, Northern Ibaraki Pref region) at a depth of 62 km with a magnitude of Mw = 4.3, the waveforms inversion was used to determine seismic moment tensor and representation it through a focal mechanism. The earthquake source is considered as a point source of seismic waves which propagate in a medium represented by a set of horizontally homogeneous elastic layers. An algorithm for determining seismic tensor components based on the forward problem solved by the matrix method, and using the generalized inverse solution, selecting only direct waves is applied. The input data for determining seismic moment components are data of only direct P waves selected from the observed records at six seismic stations of the Japanese local network NIED F-net: TSK, YMZ, ASI, ONS, SBT, KSK. The seismic moment tensor components were determined through waveform inversion using the matrix method. The obtained results, presented through a focal mechanism, are compared to the results obtained by the National Research Institute of Earth Sciences and Resistance to Natural Disasters (NIED CMT solutions). As a result of focal mechanisms comparison, it is concluded that the proposed algorithm for determining seismic moment tensor components can be used if it is impossible to use another method, or requires some refinement for another method. This approach is especially relevant for regions with low seismicity and insufficient number of stations. In addition, this method reduces the effects of an inaccurate medium model, because direct waves are much less distorted than reflected and converted, and that increases the accuracy and reliability of the method.

scholarly journals Broadband Strong-Motion Prediction for Future Nankai-Trough Earthquakes Using Statistical Green’s Function Method and Subsequent Building Damage Evaluation

2021 ◽  
Vol 11 (15) ◽  
pp. 7041
Author(s):  
Baoyintu Baoyintu ◽  
Naren Mandula ◽  
Hiroshi Kawase
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Nankai Trough ◽  
Ground Motions ◽  
Building Damage ◽  
Steel Buildings ◽  
Ground Acceleration ◽  
Attenuation Relations ◽  
Strong Ground Motions ◽  
Strong Ground

We used the Green’s function summation method together with the randomly perturbed asperity sources to sum up broadband statistical Green’s functions of a moderate-size source and predict strong ground motions due to the expected M8.1 to 8.7 Nankai-Trough earthquakes along the southern coast of western Japan. We successfully simulated seismic intensity distributions similar to the past earthquakes and strong ground motions similar to the empirical attenuation relations of peak ground acceleration and velocity. Using these results, we predicted building damage by non-linear response analyses and find that at the regions close to the source, as well as regions with relatively thick, soft sediments such as the shoreline and alluvium valleys along the rivers, there is a possibility of severe damage regardless of the types of buildings. Moreover, the predicted damage ratios for buildings built before 1981 are much higher than those built after because of the significant code modifications in 1981. We also find that the damage ratio is highest for steel buildings, followed by wooden houses, and then reinforced concrete buildings.

scholarly journals Earthquake source parameters that display the first digit phenomenon

2015 ◽  
Vol 22 (5) ◽  
pp. 625-632
Author(s):  
P. A. Toledo ◽  
S. R. Riquelme ◽  
J. A. Campos
Keyword(s):  
Seismic Moment ◽  
Waiting Times ◽  
Source Parameters ◽  
Tohoku Earthquake ◽  
Earthquake Source ◽  
Coseismic Slip ◽  
Self Organized ◽  
Earthquake Source Parameters ◽  
Self Organized Criticality

Abstract. We study the main parameters of earthquakes from the perspective of the first digit phenomenon: the nonuniform probability of the lower first digit different from 0 compared to the higher ones. We found that source parameters like coseismic slip distributions at the fault and coseismic inland displacements show first digit anomaly. We also found the tsunami runups measured after the earthquake to display the phenomenon. Other parameters found to obey first digit anomaly are related to the aftershocks: we show that seismic moment liberation and seismic waiting times also display an anomaly. We explain this finding by invoking a self-organized criticality framework. We demonstrate that critically organized automata show the first digit signature and we interpret this as a possible explanation of the behavior of the studied parameters of the Tohoku earthquake.

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