1. Name: Janette S. Manahan   

2. Organization: Philippine Institute of Volcanology and Seismology

3. Course: 1999-2000S

4. Title: Earthquake and Volcano Monitoring Network in the Philippines

5. Abstract: 
  The Philippines is situated along the Circum-Pacific Belt and is considered to be one of the most earthquake-prone countries of the world. The archipelago is bounded by oppositely-dipping subduction zones, as well as transected by a number of faults, where movements are periodically detected through the recordings of tectonic earthquakes.

  At least five imperceptible to perceptible earthquakes occur per day. However, there are some regions of the country, which are considered more earthquake prone than others, such as eastern Mindanao, Leyte and Samar which host an average of 16 felt earthquakes per year. The most recent destructive earthquakes were the July 16, 1990 Luzon earthquake (Ms = 7.8), which ¹was generated by movement along the northern segment of the Philippine Fault Zone and the November 15, 1994 Mindoro earthquake (Ms = 7.1), which likewise triggered tsunami.

  Philippine Institute of Volcanology and Seismology (PHIVOLCS) is presently the main organization body studying earthquakes in the Philippines. It is currently operating and maintaining 29 manned seismic observatories, 6 volcanological observatories and 3 telemetered stations. Each manned station is equipped with short-period seismographs operating on a 24 hour basis. Daily transmission of seismic data to the Central Office in Quezon City are done through a single-side band radios or through telephone lines. The data are processed and issued as earthquake bulletin by the Central Office. During occurrences of destructive earthquakes, PHIVOLCS responds to the crisis by sending a Quick Response Team (QRT) which conducts seismic monitoring of aftershocks, geological investigations, impact assessments and information dissemination. Likewise, PHIVOLCS also conducts public awareness programs on earthquake hazards in the Philippines and how they can be mitigated.

  By improving the earthquake monitoring and prediction capability of the Institute we may be able to minimize -- if not totally eliminate -- disasters which may arise from the occurrences of large-magnitude earthquakes in the Philippines.

 ¹: Science Research Specialist I －Seismological Observation and Earthquake Prediction Division