求翻译：菲律宾坐落于环太平洋火山地震带上，因地壳板块相互碰撞地震频发，火山活动也颇为活跃。１９７６年８月１６日，一场里氏７．９级地震突袭菲律宾南部的莫罗湾并引发海啸，导致至少５０００人死亡。是什么意思？

On the volcanoes in the Philippines is located in the Central Pacific seismic belt, by tectonic plates collide with frequent earthquakes, volcanic activity also are active. August 16, 1976, when a magnitude 7. Surprise Fabio Moro Bay in the southern Philippines 9 earthquake and tsunami, causing the deaths of at least 5,000 people.