Intensity distribution of M 4.9 Haryana–Delhi border earthquake (original) (raw)
Related papers
Seismic intensity map of South India for estimated future earthquakes
Arabian Journal of Geosciences, 2015
In this study, an attempt has been made to prepare the seismic intensity map for south India considering the probable earthquakes in the region. Anbazhagan et al. (Nat Hazards 60:1325-1345, 2012) have identified eight probable future earthquake zones in south India based on rupture-based seismic hazard analysis. Anbazhagan et al. (Eng Geol 171:81-95, 2014) has estimated the maximum future earthquake magnitude at these eight zones using regional rupture character. In this study, the whole south India is divided into several grids of size 1 o ×1 o and the intensity at each grid point is calculated using the regional intensity model for the maximum earthquake magnitude at each of the eight zones. The intensity due to earthquakes at these zones is mapped and thus eight seismic intensity maps are prepared. The final seismic intensity map of south India is obtained by considering the maximum intensity at each grid point due to the estimated earthquakes. By looking at the seismic intensity map, one can expect slight to heavy damage due to the probable earthquake magnitudes. Heavy damage may happen close to the probable earthquake zones.
Natural Hazards, 2013
We compiled available information of damages and other effects caused by the September 18, 2011, Sikkim-Nepal border earthquake from the print and electronic media, and interpreted them to obtain Modified Mercalli Intensity (MMI) at over 142 locations. These values are used to prepare the intensity map of the Sikkim earthquake. The map reveals several interesting features. Within the meizoseismal area, the most heavily damaged villages are concentrated toward the eastern edge of the inferred fault, consistent with eastern directivity. The intensities are amplified significantly in areas located along rivers, within deltas or on coastal alluvium such as mud flats and salt pans. We have also derived empirical relation between MMI and ground motion parameters using least square regression technique and compared it with the available relationships available for other regions of the world. Further, seismic intensity information available for historical earthquakes which have occurred in NE Himalayas along with present intensity has been utilized for developing attenuation relationship for NE India using two-step regression analyses. The derived attenuation relation is useful for assessing damage of a potential future earthquake (earthquake scenario-based planning purposes) for the northeast Himalaya region.
Kashmir has a long written history of 5000 years, which provides a sketchy picture of historical earthquakes. In all, we collated details of 16 earthquakes from the historical scribes. Most of the earthquakes had their epicenters outside the Kashmir Valley. The exceptions (earthquakes with epicenters within the valley), however, caused severe damage to life and properties and were associated with ground ruptures and long periods of aftershocks. Among them, only the 1885 event is adequately described. We have analyzed environmental effects of this destructive earthquake which occurred in the northwestern Kashmir Himalaya along Pir Panjal range in the early morning (5.00 a.m) of 30 May, 1885. Using archival sources followed by field work, the present attempt envisages applying the Environmental Seismic Intensity scale (ESI 2007) for a macroseismic intensity assessment of the 1885 Baramulla Earthquake. Inferences (primary and secondary) reveal that the 1885 Baramulla earthquake local intensity would have been VI–X on the ESI scale. Baramulla, the macroseismic epicenter of the earthquake, must have witnessed epicentral intensity of X on ESI scale. The intensity must have been variable, severe at Baramulla and less at Srinagar, because of the severity of damage decreased from NW to SE.
Earthquake Hazard Assessment of Peninsular India
This paper presents the detailed seismic hazard assessment of the peninsular India (lat. 8°-28°N and long. 67.5°-90°E) which is considered to be seismically most stable landmasses of the Indian plate. Past seismic history in this region (Koyna, etc) clearly shows that the seismicity of the area is varying. There were more than five damaging earthquakes with magnitudes greater than M w 6.0 have occurred in this region, stressing the importance of detailed seismic hazard assessment for the region. For India, published a probabilistic seismic hazard map based on several well identified and prominent source zones in the country. An attempt has been made in this paper to study the present seismic status of this region incorporating the seismicity, tectonic and geological characteristics and using the collected earthquake data Peak Ground Acceleration was estimated using the attenuation relation developed by Iyengar and Raghukanth (2004). Estimated PGA values were used to compute the deviation with respect to assigned PGA values for various regions provided in Indian Standard code IS 1893:2002. The results show that, the estimated PGA in many areas of the Peninsular India is more than the specified value in the current seismic macrozonation map of the country. This provides an important basis for attempting the detailed microzonation of an area within the Penisular India.
Estimation of Maximum Magnitude (M max ): Impending Large Earthquakes in Northeast Region, India
In the present study, the cumulative seismic energy released by earthquakes (M w ≥ 5) for a period of 1897 to 2009 is analyzed for northeast (NE) India. For this purpose, a homogenized earthquake catalogue in moment magnitude (M w) has been prepared. Based on the geology, tectonics and seismicity, the study region is divided into three source zones namely, 1: Arakan-Yoma Zone (AYZ), 2: Himalayan Zone (HZ) and 3: Shillong Plateau Zone (SPZ). The maximum magnitude (M max) for each source zone is estimated using Tsuboi's energy blocked model. As per the energy blocked model, the supply of energy for potential earthquakes in an area is remarkably uniform with respect to time and the difference between the supply energy and cumulative energy released for a span of time, is a good indicator of energy blocked and can be utilized for the estimation of maximum magnitude (M max) earthquakes. The proposed process provides a more consistent model of gradual accumulation of strain and non-uniform release through large earthquakes can be applied in the assessment of seismic hazard. Energy blocked for source zone 1, zone 2 and zone 3 regions is 1.35×10 17 Joules, 4.25×10 17 Joules and 7.25×10 17 Joules respectively and will act as a supply for potential earthquakes in due course of time. The estimated M max for each source zone AYZ, HZ, and SPZ are 8.2, 8.6, and 8.7 respectively. M max obtained from this model is well comparable with the results of previous workers from NE region.
Journal of Seismology, 2009
In this paper, the investigations on seismotectonic and intensity evaluations of epicentral and meizoseismal regions in Muzaffarabad earthquake—8 Oct. 2005, Mw 7.6—are summarized using The European Macroseismic Scale (EMS-98). The observations are compiled based on the field investigations and isoseismal map. The results show that the isoseismals are elongated parallel to the reactivated Muzaffarabad fault, and the attenuation is high in the direction normal to the fault compared with the direction parallel to it. The geotechnical investigations in Muzaffarabad Valley have helped the authors to assign intensity values in the localities where some huge landslides are observed. Finally, the empirical laws, previously developed for intensity attenuation in Iran in EMS-98 scale, are compared with the intensity observations here. The results are roughly consistent with the general form of attenuation laws. However, it is found that the intensity attenuations are different in the directions normal and parallel to the fault.
A STUDY ON EARTHQUAKE HAZARD ASSESSMENT IN PENINSULAR INDIA
This paper presents the detailed seismic hazard assessment of the peninsular India (lat. 8°-28°N and long. 67.5°-90°E) which is considered to be seismically most stable landmasses of the Indian plate. Past seismic history in this region (Koyna, etc) clearly shows that the seismicity of the area is varying. There were more than five damaging earthquakes with magnitudes greater than Mw 6.0 have occurred in this region, stressing the importance of detailed seismic hazard assessment for the region. For India, published a probabilistic seismic hazard map based on several well identified and prominent source zones in the country. An attempt has been made in this paper to study the present seismic status of this region incorporating the seismicity, tectonic and geological characteristics and using the collected earthquake data Peak Ground Acceleration was estimated using the attenuation relation developed by Iyengar and Raghukanth (2004). Estimated PGA values were used to compute the deviation with respect to assigned PGA values for various regions provided in Indian Standard code IS 1893:2002. The results show that, the estimated PGA in many areas of the Peninsular India is more than the specified value in the current seismic macrozonation map of the country. This provides an important basis for attempting the detailed microzonation of an area within the Penisular India.
Influence of epicentral distance on local seismic response in Kolkata City, India
Journal of Earth System Science, 2013
The influence of source and epicentral distance on the local seismic response in the Kolkata city is investigated by computing the seismic ground motion along 2-D geological cross-sections in the Kolkata city for the earthquake that occurred on 12 June 1897 (M w = 8.1; focal mechanism: dip = 57 • , strike = 110 • and rake = 76 • ; focal depth = 9 km) in Shillong plateau. For the estimation of ground motion parameters, a hybrid technique is used, which is the combination of modal summation and finite difference method. This technique allows the estimation of site specific ground motion for various events located at different distances from Kolkata city, taking into account simultaneously the position and geometry of the seismic source, the mechanical properties of the propagation medium and the geotechnical properties of the site. The epicenter of the Shillong earthquake is about 460 km away from Kolkata. The estimated peak ground acceleration (PGA) varies in the range of 0.11-0.18 g and this range corresponds to the intensity of IX to X on the Mercalli-Cancani-Sieberg (MCS) scale and VIII on the Modified Mercalli (MM) scale. The maximum amplification in terms of response spectral ratio (RSR) varies from 10 to 12 in the frequency range 1.0-1.5 Hz. These amplifications occur in correspondence to low-velocity shallow, loose soil deposit. The comparison of these results with earlier ones obtained considering the Calcutta earthquake that occurred on 15 April 1964 (M w = 6.5; focal mechanism: dip = 32 • , strike = 232 • and rake = 56 • ; focal depth = 36 km) shows that the source parameters (magnitude and focal mechanism) and epicentral distance play an important role on site response but the variation in the frequency of the peak values (RSR) is negligible. The obtained results match with observed reported intensities in Kolkata region.
Seismic hazard mapping of Delhi City
2004
Delhi the capital of India is a burgeoning metropolis having a population of some twelve million people. The city has experienced earthquakes in the past and is vulnerable for earthquake related damages in the future. There are nearby diffuse seismic sources known for their sporadic activity. In addition, the threat perception is highlighted by the proximity of the active Himalayan plate boundary region. Thus, seismic hazard at Delhi is controlled broadly by two different tectonic regimes namely, the Himalayan region (HR) and the Delhi region (DR). The present study aims at mapping the peak ground acceleration (PGA) values for Delhi city, using probabilistic seismic hazard analysis (PSHA) methods. Twenty potential faults, in a region of 300 km radius around Delhi, are identified. Recurrence relationships for the two controlling regions are established with the help of past (1720-2001A.D.) data. Regional attenuation relationship is developed using strong motion data recorded on rock ...