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2021 ◽  
Vol 8 (4) ◽  
pp. 189-192
Author(s):  
N Karunakaran ◽  
T Bayavanda Chinnappa

The challenges staring at banking today need not result in a feeling of inadequacy. The IT framework in India had strong ground and the industry has been showing significant growth rates in the previous years, with the financial sector having benefited immensely from the offerings of IT. Banks have commenced to grow laterally and at an exponential rate. As India develops into a formidable force, it is Information Technology, which holds the key to the process of transformation. The key strengths lie in knowledge processing and as bankers performing this function quite well both for customers as well as for the growth of organizations. This underlying strength will ensure the key to success.


Author(s):  
V. Melnikova ◽  
N. Gileva ◽  
Ya. Radziminovich ◽  
A. Filippova

We consider September 2, 2015, Mw=5.1 Tallay earthquake occurred in the previously aseismic area of the North-Muya Ridge adjoining to the Muya-Kuanda basin from the north. Instrumental and macroseismic data on this seismic event are presented. Its seismic moment tensor is calculated from surface wave amplitude spectra. New data on strong ground motions are obtained within the north-eastern flank of the Baikal rift. The Tallay earthquake is found to be connected with seismogenic renewal of the second-order multidirectional faults activated in the rift stress field.


2021 ◽  
Author(s):  
Shiliang Zhang ◽  
Dongwang Tao ◽  
Quancai Xie ◽  
Qiang Ma ◽  
Fuchen Wang

Abstract Strong horizontal ground motions with the peak ground acceleration (PGA) larger than 1400 gal were observed at Yamamoto (MYGH10) station during the February 2021 Mj 7.3 off the east coast of Honshu, Japan, Fukushima earthquake. Firstly, in this paper, we discussed and verified the theoretical assumptions of the “Nakamura” method under weak and strong ground motions. The site amplification factor of the MYGH10 station was estimated using the surface horizontal-vertical spectral ratio (HVSR) and the surface-to-borehole spectral ratio (SBSR), and the corrected HVSRC, respectively. Meanwhile, the reasons for underestimating the site amplification factor when using HVSR were explained. The vertical amplification phenomenon of seismic P-wave in the high-frequency band was analysed under weak and strong ground motions. Secondly, we utilized HVSR, SBSR, and theoretical transfer function (TTF) based on the 1D wave propagation theory to study the nonlinear site response of MYGH10 station under the mainshock of the Fukushima earthquake and the historically weak and strong ground motions, respectively. The changes in frequencies and amplitudes of the spectral ratio curves when nonlinearities were occurring at the site were analysed and compared using the spectra ratio curves of weak ground motion records and TTF as references. Finally, the recovery of the site after strong nonlinearity was also evaluated by comparing the spectral ratio curves of aftershocks records. We found that the most significant amplification factor of the site increased from 7 to more than 10, and the predominant frequency decreased from 10 Hz to 3.8 Hz under the mainshock of the Fukushima earthquake. The predominant frequency returned to the previous value within three days after the mainshock, but the amplification factor did not.


Geology ◽  
2021 ◽  
Author(s):  
Alba M. Rodriguez Padilla ◽  
Michael E. Oskin ◽  
Thomas K. Rockwell ◽  
Irina Delusina ◽  
Drake M. Singleton

Large, multi-fault earthquakes increase the threat of strong ground shaking and reshape the probability of future events across a system of faults. Fault junctions act as conditional barriers, or earthquake gates, that stop most earthquakes but permit junction-spanning events when stress conditions are favorable. Constraining the physical conditions that favor multi-fault earthquakes requires information on the frequency of isolated events versus events that activate faults through the junction. Measuring this frequency is challenging because dating uncertainties limit correlation of paleoseismic events at different faults, requiring a direct approach to measuring rupture through an earthquake gate. We show through documentation and finite-element modeling of secondary fault slip that co-rupture of the San Andreas and San Jacinto faults (California, USA) through the Cajon Pass earthquake gate occurred at least three times in the past 2000 yr, most recently in the historic 1812 CE earthquake. Our models show that gate-breaching events taper steeply and halt abruptly as they transfer slip between faults. Comparison to independent chronologies shows that 20%–23% of earthquakes on the San Andreas and the San Jacinto faults are co-ruptures through Cajon Pass.


2021 ◽  
Vol 576 ◽  
pp. 117237
Author(s):  
Elisa Tinti ◽  
Emanuele Casarotti ◽  
Thomas Ulrich ◽  
Taufiq Taufiqurrahman ◽  
Duo Li ◽  
...  

2021 ◽  
Vol 11 (23) ◽  
pp. 11152
Author(s):  
Mio Kobayashi ◽  
Toshihiro Noda ◽  
Kentaro Nakai ◽  
Toshihiro Takaine ◽  
Akira Asaoka

Safety measures are required for spherical gas holders to prevent them from malfunctioning even after a large earthquake. In this study, considering the strong nonlinearity of the ground and damage to the pile during an earthquake, a three-dimensional seismic response analysis of the holder–pile–ground interaction system was conducted for an actual gas holder on the soft ground consisting of alternating layers of sand and clay. In the analysis, the seismic response of the structure to strong ground motions of different durations with the same acceleration response spectrum was verified. The results show that the piles were relatively effective in controlling the settlement when the duration of the earthquake motion was long. This is because the axial force acting on the pile increased due to the redistribution of the holder load caused by the lowering of the effective confining pressure of the sand and clay layers during the earthquake, which increased the bearing capacity of the pile. In contrast, when the duration of the seismic motion was short, the piles had little effect on the reduction in the settlement because the maximum acceleration was higher than that in the former case, and the piles immediately lost their support function.


2021 ◽  
Vol 64 (4) ◽  
pp. SE432
Author(s):  
Iren-Adelina Moldovan ◽  
Angela Petruta Constantin ◽  
Raluca Partheniu ◽  
Bogdan Grecu ◽  
Constantin Ionescu

The goal of this paper is to develop a new empirical relationship between observed macroseismic intensity and strong ground motion parameters such as peak ground acceleration (PGA) and velocity (PGV) for the Vrancea subcrustal earthquakes. The recent subcrustal earthquakes provide valuable data to examine these relationships for Vrancea seismogenic region. This region is one of the most active seismic zones in Europe and it is well-known for the strong subcrustal earthquakes. We examine the correlation between the strong ground-motion records and the observed intensities for major and moderate earthquakes with Mw ≥ 5.4 and epicentral intensity in the range VI to IX MSK degrees that occurred in Vrancea zone in the period 1977-2009. The empirical relationships between maximum intensity and ground parameters obtained and published by various authors have shown that these parameters do not always show a one-to-one correspondence, and the errors associated with the intensity estimation from PGA/PGV are sometimes +/-2 MSK degree. In the present study, the relation between macroseismic intensity and PGA/PGV will be given both as a mathematical equation, but also as corresponding ground motion intervals. Because of the intensity data spreading and errors related to mathematical approximations, it is necessary to systematically monitor not only the acceleration and velocity but also all the other ground motion parameters. The mathematical relation between these parameters might be used for the rapid assessment of ground shaking severity and potential damages in the areas affected by the Vrancea earthquakes.


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