National Seismological Centre: An Overview, Prospects and Challenges By Soma Nath Sapkota Department of Mines and Geology National Seismological Centre Nepal
India Himalaya Tibetan Plateau India continental t convergence 1.8 m/century
India Himalaya Tibetan Plateau India continental t convergence 1.8 m/century
critical stress India Himalaya Tibetan Plateau India continental t convergence 1.8 m/century
India great earthquake 4-10 m Himalaya Tibetan Plateau time since last earthquake is a measure of size of next earthquake
About 50 million people living in Ganges plain are at risk from impending great Himalayan earthquakes, However, Surface rupture of most of the past earthquake are not found Return R t period undetermined d
Activities ities of NSC Monitoring of Earthquake Crustal Deformation Monitoring Paleoseismology Precursor Monitoring Preparation of Seismic Hazard and Risk Map Public Awareness for Teachers, Technical Personnel & Engineers
Our International national Collaborators ato 1. DASE (Departmment, Analyse Surveillance, Environnment ( Since 1978 ) 2. California Institute of Technology USA since 2001 Monitoring crustal deformation by establishing a network of GPS stations in collaboration with DASE. 3. IPGP ( Istitut de Physique du Globe de Paris, France ) 4. JICA ( Providing training for NSC/DMG staffs)
Objectives of National Seismological Centre Acquire seismic data by operating seismological network with high level of efficiency and provide the earthquake information to Home Ministry and other media to conduct search and rescue work immediately in case of potentially destructive ti earthquakes through h the seismic i alert system installed with in the system in NSC lab. Evaluation of seismic hazard of the country using the seismic data and other available geophysical, geological and geodetic data. Provide seismic bulletins to NEIC, ISC, USGS and contribute towards global seismological research. Conduct basic and applied research in the field of earthquakes in collaboration with various international and national scientific institution to mitigate the seismic hazard in the Himalayan region.
National Seismological Network
Seismic Vault
NSC Informs When It Detects>4.0 mag earthquake Earthquake >4.0 (Ml) Automatic Phone Call to Responsible Person Processing of the Earthquake data Localization of the Earthquake (20Minutes) Fax+Phone+website update Release of the Earthquake information to Radio, RSS, TVs, Home ministry and on official website www.seismonepal.gov.np
Press Released Eveents from 1994 to 2006
Original model: Seeber and Armbruster, 1981 Contours of microseismicity: Pandey et al., 1995
Purposed Accelerometer stations with historical earthquakes in background
Seismic and accelerometric network NSC seismic network 21 short period velocimetric i stations ti (1 component z) Allow deriving accelerations for most earthquakes recorded in Nepal, a necessary input to SHA model Stations in acquisition Pending installations Need for accelerometric stations Because the dynamic of the velocimetric station is not enough to cover the whole range from very small to large earthquakes es at short distances Accelerometric stations will therefore complement the existing seismic network: Since 2009, 3 stations are in acquisition in KKN, DMG, PKR
Locked Fault Zone (Bettinelli et al, 2006) The GPS data indicate that the MHT is Locked at depth less than about 20km and is creeping at about 20mm/yr below the high range and southern Tibet
Precursor Monitoring Radon Gas Monitoring
Sir Khola natural exposure dating Radiocarbon Dating from 2008 and 2009 work
Charnath Megatrench preliminary field interpretation Central part of East Wall W E F3
Charnath Megatrench preliminary field interpretation Northern part of East Wall W E F1 Boulder Bed F2
Future Prospects and Challenges 1. We have collected handful data from numbers of collaborative projects, we are in the process of extracting the necessary information from those data to address seismic hazard of the region. 2. DMG is a government organization and we are committed to provide the seismic Hazard and risk map of the country and microzonation study of big cities like Kathmandu, part of our research activities should focus in this direction. 3. For precise localisation of the earthquake we need to deploy some temporary stations in the north of microseismicity belt so that we could constrain the depth. 4. We have conducted many collaborative research in central Nepal section similar types of research should be conducted in western and far western Nepal (so called seismic gap) contd
Conclusion National Seismological Centre is emerging as a research centre for earthquake studies in this region Active tectonics and Structure of the crust and upper mantle across the central Nepal has been investigated with varieties of techniques. To quantify the seismic gap between 1934 and 1905 Earthquake our research activities i i should be focused in that area i.e. Western and Far-Western area. Segmentation of Himalayan arc, source delineation and attenuation factors should be developed and refined with new data set Scientific collaboration with other scientific institutions should also focus on applied issues like preparation of deterministic seismic hazard map of the country, microzonation studies of big cities of Nepal.