Research Project on Seismic Microzonation in Metro Manila-Estimation of Ground Dynamic Amplification Characteristics by Microtremor Observation-

以下是本项目的研究项目。(1)根据地质地貌条件进行区域划分。利用该区钻孔资料，绘制了地貌分类图和若干地质剖面。(2)微震观测。利用微震观测，绘制了该地区的优势周期分布图和放大比分布图。(3)利用爆炸试验估算马里基纳平原地下深层结构进行了爆炸试验，并观测了约15km线上的地震波，估算了地下结构的s波速度。(4)浅层横波速度勘探在马尼拉大都会地区的23个测点进行了浅层地震折射勘探。(5)微震的阵列观测在4个站点进行了微震的阵列观测。(6)马里基纳断层2个测点电法测量应用电层析成像方法确定了马里基纳断层的正确位置和构造。(7)地震观测为了获取地震记录，我们在雅典耀大学马尼拉天文台安装了一台强震仪。到目前为止，地震仪获得了8次地震的地震图。通过这些研究项目的结果，我们了解了马尼拉大都会的地质条件，我们可以为该地区的地震减灾研究提供基础数据。1998年3月9日至10日，与3个国际研究小组在关东学院大学Hayama研讨会馆里举行了地震微带研讨会，并发表了论文摘要。每次演讲的论文全文将在不久的将来作为关东学院大学科学技术研究所公报的特刊发表。

Followings are research items in this project.(1) Regional division on the basis of geological and geomorphological conditionsUsing of bore hole data in the area, a land form classification map and several geologic cross-sections were developed.(2) Microtremor observations.Distribution maps of predominant period and amplification ratio in the area had been made by observed microtremor.(3) Estimation of under ground deep structure with explosion test in Marikina PlaneExplosion test had been conducted and observed seismic waves on about 15km line to estimate the under groud structure of S-wave velocities.(4) Shallow S-wave Velocity ExplorationShallow seismic refraction explorations were conducted in Metro Manila at 23 sites.(5) Array observation of microtremor Aarray observations of microtremor had been conducted at four sites.(6) Electric surveys at 2 sites for Marikina FaultThe electrical tomography method were applied to found the correct position and structure of Marikina Fault.(7) Observation of EarthquakeIn order to acquire seismograms, we installed a strong seismograph at Manila Observatory at Ateneo University. The seismographs up to date acquired the seismograms for eight earthquakes.By those results of each research items, we had understand of the geological conditions in Metro Manila and we can offer the basic data to the seismic mitigation research in the area.Joint research meeting with 3 international research groups had been conducted as Workshop on Seismic Microzonation at March 9-10,1998, in Hayama Seminar House of Kanto Gakuin University and published a proceedings of abstracts. The proceedings of full papers fo each presentation will be published in near future as a special isue of the Bulletin of Institute of Science and Technology, Kanto Gakuin University.