national seismological centre: an overview, prospects and...

National Seismological Centre: An Overview,Prospects and Challenges

BBy Soma Nath Sapkota

Department of Mines and GeologyNational Seismological Centreg

Nepal

Tibetan PlateauHimalayaIndia

India

ti t l continental convergence1 8 m/century1.8 m/century

critical stress


India

ti t l continental convergence1 8 m/century1.8 m/century

great earthquake4-10 m4 10 m


time since last earthquake is a measure of size of next earthquakesize of next earthquake

About 50 million people living in Ganges plain are at riskin Ganges plain are at risk from impending great Himalayan earthquakes,

However,

•Surface rupture of most of the past earthquake are not found

R t i d d t i d•Return period undetermined

Acti ities of NSCActi ities of NSCActivities of NSCActivities of NSC

Monitoring of EarthquakeMonitoring of EarthquakeCrustal Deformation MonitoringCrustal Deformation MonitoringggPaleoseismologyPaleoseismologyPrecursor MonitoringPrecursor MonitoringPrecursor MonitoringPrecursor MonitoringPreparation of Seismic Hazard and Risk Preparation of Seismic Hazard and Risk MapMapMapMapPublic Awareness for Teachers, Technical Public Awareness for Teachers, Technical Personnel & EngineersPersonnel & EngineersPersonnel & EngineersPersonnel & Engineers

O Inte national Collabo ato sO Inte national Collabo ato sOur International CollaboratorsOur International Collaborators

1. DASE (Departmment, Analyse Surveillance, 1. DASE (Departmment, Analyse Surveillance, Environnment ( Since 1978 )Environnment ( Since 1978 )

2. California Institute of Technology USA since 2001 2. California Institute of Technology USA since 2001 Monitoring crustal deformation by establishing a Monitoring crustal deformation by establishing a network of GPS stations in collaboration with DASE.network of GPS stations in collaboration with DASE.

3.3. IPGP ( Istitut de Physique du Globe de Paris, France )IPGP ( Istitut de Physique du Globe de Paris, France )44 JICA ( Providing training for NSC/DMG staffs)JICA ( Providing training for NSC/DMG staffs)4.4. JICA ( Providing training for NSC/DMG staffs) JICA ( Providing training for NSC/DMG staffs)

Objectives of National Seismological CentreAcquire seismic data by operating seismological networkAcquire 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 d t ti th k th h th i i l t tdestructive earthquakes through the seismic alert system installed with in the system in NSC lab.

Evaluation of seismic hazard of the country using theEvaluation 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 h d i h Hi l ihazard in the Himalayan region.

National Seismological NetworkNational 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)Localization of the Earthquake (20Minutes)

Fax+Phone+website update

Release of the Earthquake information to Radio, RSS TVs Home ministry and on official

Fax Phone website update

RSS, TVs, Home ministry and on official website www.seismonepal.gov.np

Press Released Eveents from 1994 to 2006

Original model: Seeber and Armbruster, 1981Contours of microseismicity: Pandey et al., 1995

Purposed Accelerometer stations with historical earthquakes in background

Seismic and accelerometric networkSeismic and accelerometric networkNSC seismic network21 h t i d l i t i t ti (1 t )•21 short period velocimetric stations (1 component z)

Allow deriving accelerations for most earthquakes recorded in Nepal, a necessary input to SHA modelnecessary 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 at short distances a ge o e y s a o a ge ea qua es a s o d s a cesAccelerometric stations will therefore complement the existing seismic network: Since 2009, 3 stations are in acquisition in KKN, DMG, PKR

Locked Fault ZoneLocked Fault Zone

The GPS data indicate that the MHT is Locked at The GPS data indicate that the MHT is Locked at depth less than about 20km and is creeping at depth less than about 20km and is creeping at

(Bettinelli et al, 2006)

p p gp p gabout 20mm/yr below the high range and about 20mm/yr below the high range and

southern Tibetsouthern Tibet

Precursor Monitoring Radon Gas Monitoring

Sir Khola natural exposure datingRadiocarbon Dating from 2008 and 2009 work

Charnath Megatrench preliminary field interpretationCentral part of East Wall

EW

E

F3

Charnath Megatrench preliminary field interpretationNorthern part of East Wall

W E

F1

Boulder Bed F2

Future Prospects and ChallengesFuture 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.data to address seismic hazard of the region.

2. DMG is a government organization and we are committed to provide theseismic Hazard and risk map of the country and microzonation p ystudy of big cities like Kathmandu, part of our research activitiesshould focus in this direction.

3. For precise localisation of the earthquake we need to deploy someh h f b l htemporary stations in the north of microseismicity belt so that we

could constrain the depth.

4 We have conducted many collaborative research in central Nepal section4. We have conducted many collaborative research in central Nepal section similar types of research should be conducted in western and farwestern Nepal (so called seismic gap)

contdcontd………

ConclusionConclusionNationalNational SeismologicalSeismological CentreCentre isis emergingemerging asas aa researchresearch centrecentreff h kh k didi ii hihi iiforfor earthquakeearthquake studiesstudies inin thisthis regionregion

ActiveActive tectonicstectonics andand StructureStructure ofof thethe crustcrust andand upperupper mantlemantleacrossacross thethe centralcentral NepalNepal hashas beenbeen investigatedinvestigated withwith varietiesvarieties ofofacrossacross thethe centralcentral NepalNepal hashas beenbeen investigatedinvestigated withwith varietiesvarieties ofoftechniquestechniques..

ToTo quantifyquantify thethe seismicseismic gapgap betweenbetween 19341934 andand 19051905E h kE h k hh i i ii i i h ldh ld bb f df d ii hhEarthquakeEarthquake ourour researchresearch activitiesactivities shouldshould bebe focusedfocused inin thatthatareaarea ii..ee.. WesternWestern andand FarFar--WesternWestern areaarea..

SegmentationSegmentation ofof HimalayanHimalayan arcarc sourcesource delineationdelineation andandSegmentationSegmentation ofof HimalayanHimalayan arc,arc, sourcesource delineationdelineation andandattenuationattenuation factorsfactors shouldshould bebe developeddeveloped andand refinedrefined withwith newnewdatadata setset

S i tifiS i tifi ll b till b ti ithith thth i tifii tifi i tit tii tit ti h ldh ldScientificScientific collaborationcollaboration withwith otherother scientificscientific institutionsinstitutions shouldshouldalsoalso focusfocus onon appliedapplied issuesissues likelike preparationpreparation ofof deterministicdeterministicseismicseismic hazardhazard mapmap ofof thethe country,country, microzonationmicrozonation studiesstudies ofofbigbig citiescities ofof NepalNepal..

national seismological centre: an overview, prospects and...

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