It has taken more than a hundred years for seismic observations in the Philippines to evolve to a modern observation system. The responsibility of seismic observations was likewise transferred from one agency to anoth...It has taken more than a hundred years for seismic observations in the Philippines to evolve to a modern observation system. The responsibility of seismic observations was likewise transferred from one agency to another during this same period of time. At present, the mandate of conducting seismic observations in the Philippines rests with the Philippine Institute of Volcanology and Seismology (PHIVOLCS). In 2000, through a grant aid from the Japan International Cooperation Agency (JICA), the Philippine seismic network was upgraded to a digital system. As a result, a new set of seismic monitoring equipments was installed in all of the 34 PHIVOLCS seismic stations all over the country. Digital waveforms are now available for high level seismic data processing, and data acquisition and processing are now automated. Included in the upgrade is the provision of strong motion accelerographs in all stations whose data can now be used for studying ground motion and intensity attenuation relations. The new setup is now producing high-resolution data that can now be used for conducting basic seismological researches. Earthquake locations have now improved allowing for the modeling and delineation of earthquake source regions necessary for earthquake hazard studies. Current seismic hazard studies in the Philippines involve the estimation of ground motion using both probabilistic and deterministic approaches, seismic microzonation studies of key cities using microtremor observations, paleoseismology and active faults mapping, and identification of liquefaction-prone, landslide-prone and tsunami-affected areas. The earthquake database is now being reviewed and completed with the addition of historical events and from data from regional databases. While studies of seismic hazards were primarily concentrated on a regional level, PHIVOLCS is now focusing on doing these seismic hazard studies on a microlevel. For Metro Manila, first generation hazard maps showing ground rupture, ground shaking and liquefaction hazards have recently been completed. Other large cities that are also at risk from large earthquakes are the next targets. The elements at risk such as population, lifelines, and vertical and horizontal structures for each of these urban centers are also being incorporated in the hazard maps for immediate use of planners, civil defense officials, policy-makers and engineers. The maps can also now be used to describe possible scenarios during times of strong events and how appropriate socio-economic and engineering responses could be designed. In addition, a rapid earthquake damage assessment system has been started which will attempt to produce immediate or rapid assessments including identification of elements at risk during times of strong earthquakes.展开更多
文摘It has taken more than a hundred years for seismic observations in the Philippines to evolve to a modern observation system. The responsibility of seismic observations was likewise transferred from one agency to another during this same period of time. At present, the mandate of conducting seismic observations in the Philippines rests with the Philippine Institute of Volcanology and Seismology (PHIVOLCS). In 2000, through a grant aid from the Japan International Cooperation Agency (JICA), the Philippine seismic network was upgraded to a digital system. As a result, a new set of seismic monitoring equipments was installed in all of the 34 PHIVOLCS seismic stations all over the country. Digital waveforms are now available for high level seismic data processing, and data acquisition and processing are now automated. Included in the upgrade is the provision of strong motion accelerographs in all stations whose data can now be used for studying ground motion and intensity attenuation relations. The new setup is now producing high-resolution data that can now be used for conducting basic seismological researches. Earthquake locations have now improved allowing for the modeling and delineation of earthquake source regions necessary for earthquake hazard studies. Current seismic hazard studies in the Philippines involve the estimation of ground motion using both probabilistic and deterministic approaches, seismic microzonation studies of key cities using microtremor observations, paleoseismology and active faults mapping, and identification of liquefaction-prone, landslide-prone and tsunami-affected areas. The earthquake database is now being reviewed and completed with the addition of historical events and from data from regional databases. While studies of seismic hazards were primarily concentrated on a regional level, PHIVOLCS is now focusing on doing these seismic hazard studies on a microlevel. For Metro Manila, first generation hazard maps showing ground rupture, ground shaking and liquefaction hazards have recently been completed. Other large cities that are also at risk from large earthquakes are the next targets. The elements at risk such as population, lifelines, and vertical and horizontal structures for each of these urban centers are also being incorporated in the hazard maps for immediate use of planners, civil defense officials, policy-makers and engineers. The maps can also now be used to describe possible scenarios during times of strong events and how appropriate socio-economic and engineering responses could be designed. In addition, a rapid earthquake damage assessment system has been started which will attempt to produce immediate or rapid assessments including identification of elements at risk during times of strong earthquakes.
