HR: 1400h
AN: S33B-05    [Abstracts]
TI: Development of Earthquake Hazard Maps in Managua, Nicaragua
AU: Nishii, O
EM: nishii@oyointer.com
AF: OYO International Corporation, 6 Rokubancho, Chiyoda-ku, Tokyo, 1020085, Japan
AU: Katayama, I
EM: tg043361@tigers-net.com
AF: Association for the Development of Earthquake Prediction, 1-5-18 Sarugakucho, Chiyodaku, Tokyo, 1010064, Japan
AU: * Strauch, W
EM: wilfried.strauch@gf.ineter.gob.ni
AF: Instituto Nicaraguense de Estudios Territoriales, Dirección General de Geofísica, Frente a Policlínica Oriental, Managua, Nicaragua
AU: Guzman, C
EM: carlos.guzman@gf.ineter.gob.ni
AF: Instituto Nicaraguense de Estudios Territoriales, Dirección General de Geofísica, Frente a Policlínica Oriental, Managua, Nicaragua
AU: Chávez, G
AF: Instituto Nicaraguense de Estudios Territoriales, Dirección General de Geofísica, Frente a Policlínica Oriental, Managua, Nicaragua
AB: We developed 1/50,000 scale earthquake hazard maps in Managua by deterministic and probabilistic approach, compiling available data. This is a part of the result obtained by the technical cooperation - The Study for Establishment of Base Maps for GIS in the Republic of Nicaragua - during the year from 2004 to 2006 executed by Japan International Cooperation Agency with INETER as a counterpart agency upon the request by the government of the Republic of Nicaragua. We firstly collected and studied available earthquake catalogues. Among these catalogues, the historical earthquake catalogue by INETER (1505 - 1992) and instrumental earthquake catalogue by INETER (1993 - 2001) are the most comprehensive. Therefore these catalogs are selected as the base catalog and corrected and improved using other catalogues. Finally, these catalogs are unified, and then separated into two new catalogs namely Volcanic Catalogs and Non-volcanic Catalog. Then we considered three types of scenario earthquakes. For earthquake scenario from active fault, we used Aeropuerto Fault and Cofradia Fault. The location and magnitude of each fault are determined using USGS fault map and empirical formula on its length and magnitude. For earthquake scenario by volcanic earthquake, we used earthquake from Masaya volcano (M=6.0) and the one from Apyoque volcano (M=6.0). Magnitudes of these earthquakes are estimated from the past reports of the hazards. As for the probabilistic approach, based on the newly improved the Non-volcanic Catalog, hazard curve analysis is performed at the Center of Managua City. As a result, the 100-years-return period earthquake is obtained as 110 gal with the standard deviation of 28 gal. For the ground motion attenuation, three types of attenuation laws were tested to estimate maximum accelerations and MM Intensities at Managua by major earthquakes. As a result, we found that combined law of Joyner-Boore (1981) and Young et al. (1997) are appropriately applicable to the historical records and accelerations of both non-volcanic and volcanic events. As for the site effect, boring logs from 173 boreholes are collected and studied. We found that there is no obvious variety of the subsurface soil characteristics and their thicknesses at Managua City area. Through the study, the Study area is classified into three types based on the average S wave velocity over upper 30m standardized by NEHRP (FEMA302). Finally, earthquake hazard maps were prepared representing ground motion by peak ground acceleration, using 500 m square grid system.
DE: 7212 Earthquake ground motions and engineering seismology
DE: 7280 Volcano seismology (8419)
DE: 9360 South America
SC: Seismology [S]
MN: 2007 Joint Assembly