ESARSWG: Background and Current status Atalay Ayele AfricaArray 2 nd Workshop Palmanova, Italy February 26-27, 2005

CONTENT 1.History 2.Current status with respect to its recent past 3.Current activities 4.Problems 5.Plans in the years ahead 6.Ethiopian case?

Seismicity after Sieberg and Krenkel Rare or unknown Moderately frequent not violent Frequent occasionally destructive World-shaking shocks

WWSSN era since 1960s PLUS GDSN HLW, AAE, BUL, LWI? KLMBO, LSZ FURI, ATD, LBTB, BGCA etc

There are a lot of events passing unnoticed at local scale b/se of poor station distribution and technology

ESARSWG formed The first activity of ESARSWG started in 1993 in Dar es Selam Participating countries were: Eritrea, Ethiopia, Kenya, Uganda, Tanzania, Zambia, Malawi, Zimbabwe Funded mainly by IPPS (International Program in the Physical Sciences) of UU Prof. Lennart.Hasselgren played a major role University of Bergen through Prof. Jens Havskov in training and data analysis using SEISAN

Seismic Stations in the region at the beginning

Data analysis Mainly to produce bulletin At the beginning it was clumsy and costly b/se people have to carry seismograms to the analysis center Then we started to bring phase readings of each country on a floppy At the present we exchange data by and only one country processes the data and prepares the bulletin on a rotation basis

Training Many PhD and Msc students have been trained in Bergen and Uppsala That is a great capacity building in seismology in Africa Many technicians have been trained also at regional centers or in Norway and Sweden

Current status of seismic stations No.CountrySTAtn Type of instrument SeismCompRecordClockPeriodP.status 1EritreaASMES-131SZA/LenarzRadio1986-Operat. SHBEGeophon3SZGeoSIGGPS2003Operat GELEGeophon3SZGeoSIGGPS2003Test ABSEL4C1SZD/NanomGPS1998-Operat. 2 Ethiopia AAEBeinoff3SZNEA/WWSSNRadio1959-Operat. FURICMG-3T3BBZNEQuanteraGPS1997-Operat DESELe-3d/53SZNERef.DASGPS1989-Operat. WNDELe-3d/53SZNERef.DASGPS1985-Operat. ALMELe-3d/53SZNERef.DASGPS1986-Operat. 3 Uganda ENTL4C CMG-40T L4-3D 1SZ 3BZNE 3SZNE A/MEQ800 D/SEISLOG D/ORION GPS Operat. Down Operat. MBAR KS CMT-3T 3BZNE 3SZNE D/MK-71SP-D GPS 1995-Operat. KILL4C L4-3D 1SZ 3SZNE A/MEQ-800 D/ORION GPS 1990-Operat. HOIL4C L4-3D 1SZ 3SZNE A/MEQ-800 D/ORION GPS 1991Operat. 4 Kenya MAGLe-3d/53SZNED/Zip driveGPS1994-Down KMBOIRIS3BZNED/IRISGPS1995-Operat. MERLe-3d/53SZNED/MARS88GPS1997-Down LANLe-3d/53SZNED/MARS88GPS1997-Operat. NAILe-3d/53SZNED/SEISLOGGPS1995-Operat. 5 Tanzania MOROL4-C3SZNED/ORIONGPS Operat. MBAL4-C3SZNED/ORIONGPS Operat. ARTTL4-C3BZNED/ORIONGPS1991-Operat. DOTL4-C3SZNED/ORIONGPS1990-Operat.

NoCNTRYSTN TYPE OF INSTRUMENT SeismCompRecordClockPeriodPresent status 6 Malawi CLKS-133SZNEA/EARSS.Radio1962-Operational ZOML4-C1SZA/TELEDRadio1989-Down MALL4-C1SZEARSSIG 1989-Operational MAZ M L4-C1SZEARSSIG 1989-Operating LIL M L4-C1SZEARSSIG 1989-Operational 7 Zambia LSZStrakes3C,VBB ZNE D/IRISGPS1994-Operational KMZLennartz3C, SP ZNE D/ReftekGPS1998-dateDown MZZLennartz3C, SP ZNE D/ReftekGPS1998-dateDown IKZLennartz3C, SP ZNE D/ReftekGPS1998-dateDown PTZLennartz3C, SP ZNE D/ReftekGPS1998-dateDown 8 Zimbabwe BULBenioff 3SZNE 3LZNE A/WWSSN Radio Down BULS-133SZNEA/Radio Down MTDS-131SZA/Radio Down CIRS-131SZA/Radio Down KRIS-131SzA/Radio Down

Current activities Bulletin preparation is going on A workshop was held in Bulawayo, Zimbabwe from Feb.7 – Feb. 11, 2005 The objective was to train seismogram analysts –The content of the training was more or less on: Intro. to seismic wave propagation Intro. to seismology and plate tectonics Digital filtering Phase picking and event locations (manually & with comp.) Magnitude estimates Demonstrating software like: SEISAN, DIMAS, PITSA, SAC

Problems Lack of funding for station operations in all countries (at least running cost) – respective governments are not involved in funding or even not aware of the benefit of running seismic station network Fragile data archiving system Vandalism of equipments, specially in field Lack of spare parts of hardware and competent expertise to maintain stations Brain drain

Future plans To make governments aware of the problem Training more Msc and PhD students in the region Do much research on seismology and improve seismic hazard map of the region

The Ethiopian case 1CMG-3T G. & 1 Le-3d/5s are spare 1 DAS is not operating and sent to RefTek for maintenance

ALME station installation

Frequency content of Le-3d/5s record

Melka-Sedi (near DOFEN) earthquake as picked by ALME station (Le-3d/5s)

The December 26, 2004 earthquake in Indonesia as recorded at our station FURI

Our location for the Indonesian earthquake using only our one station

The December 26, 2004 event at WNDE (Le-3d/5s )

The December 26, 2004 event at DESE (Le-3d/20s )