By Ellalyn De Vera-Ruiz Weeks after Mindanao was struck by a series of powerful earthquakes, the Philippine Institute of Volcanology and Seismology (Phivolcs) urged the public to actively participate in an earthquake and tsunami drill to be held on Thursday. Philippine Institute of Volcanology and Seismology (MANILA BULLETIN)  The Nationwide Simultaneous Earthquake and Tsunami Drill, which will start at 9 a.m., Thursday, is being conducted in commemoration of the 25th anniversary of the 1994 Mindoro earthquake and tsunami. As the country is prone to strong earthquakes and tsunamis, Science and Technology Undersecretary and Phivolcs Director Renato Solidum said the public should prepare and properly respond to these "sudden-onset events." "We encourage the (coastal) communities and the public to join in the Nationwide Simultaneous Earthquake and Tsunami Drill to test their preparedness and response plans," Solidum said. All coastal areas in the Philippines can be affected by tsunamis generated mostly by under-the-sea earthquakes, sometimes by submarine landslides or volcanic eruptions. A locally-generated tsunami can arrive in minutes, making it important to recognize the natural signs – “shake, drop, and roar.” Solidum explained that these natural signs mean strong ground shaking, drop or sudden change in the sea level, and roaring sound of incoming waves. This year marks the 25th anniversary of a 7.1-magnitude earthquake, which hit Mindoro on November 15, 1994.