000019885 001__ 19885
000019885 005__ 20170118182341.0
000019885 04107 $$aeng
000019885 046__ $$k2017-01-09
000019885 100__ $$aTaborda, Ricardo
000019885 24500 $$aA Three-Dimensional Regional-Scale Earthquake Ground Motion Simulation for the Bengal Basin

000019885 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000019885 260__ $$b
000019885 506__ $$arestricted
000019885 520__ $$2eng$$aThis study presents the initial results of a project with the goal of studying the ground motion characteristics of the Bengal basin region in Bangladesh, south Asia, through the simulation of a series of historical, recorded and scenario earthquakes. Bangladesh is one of the most densely populated countries in the world, with more than one thousand people per square kilometer, and several cities exceeding a few millions habitants. Most people in Bangladesh live in poorly constructed (often unreinforced) buildings. The country land is shaped by the Ganges delta, the largest delta system in the world, which rests over a sedimentary structure with thicknesses that can reach up to 20 km. The lithospheric structure is dominated by the different orogeny systems created by the collision between the Indian, Eurasian and Burmese tectonic plates. Depending on the geological setting, Bangladesh can be divided into three provinces: the stable shelf, which is part of the Indian continental plate at the northwest; the central deep basin, covering most of Bangladesh; and the Chittagong-Tripura fold belt at the eastern border, created by the oblique subduction of the oceanic crust under the Burmese plate. The region is bounded by the Dauki fault to the north and north-east, the Bogra fault on the stable shelf region, boundary thrust faults at Chittagong-Tripura fold belt region to the east, and the Madhupur fault and some other ambiguous faults inside the basin. These systems place Bangladesh under high seismic hazard, and given the population density and infrastructure conditions it is assumed the country presents elevated levels of seismic risk. This situation is worsen by the tremendous scarcity of seismic data, despite the significant seismic activity in the region. Under these conditions, simulations can provide valuable input to better understand the potential effects of a major earthquake affecting the Bengal basin. However, in order to perform ground motion simulations, the first step is to construct a reliable seismic velocity model for the region. Here, we present the initial version of a three-dimensional model built upon a geology-based representation of the geometry of the Bengal basin and simple approximations of the basin deposits, crustal, and background structures. We show results for a low-frequency ground motion simulation ( f ≤ 0.5 Hz) of the 10 September 2010 Mw 5.1 Chandpur earthquake and compare basic qualitative characteristics observed in the synthetics with a limited number of records available. The simulations are done using a finite-element parallel code. Using these initial results we investigate the influence of basic features such as fault boundaries and basin depth, and shed light over future steps necessary to better characterize earthquake ground motions in the region.

000019885 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000019885 653__ $$aBengal basin; Bangladesh; deep basin effects; ground motion simulation, seismic velocity model

000019885 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000019885 720__ $$aTaborda, Ricardo$$iHuda, Md. Monsurul
000019885 8560_ $$ffischerc@itam.cas.cz
000019885 8564_ $$s1535792$$uhttps://invenio.itam.cas.cz/record/19885/files/4606.pdf$$yOriginal version of the author's contribution as presented on USB, paper 4606.
000019885 962__ $$r16048
000019885 980__ $$aPAPER