The Philippines is susceptible to many natural hazards, including earthquakes, landslides, tsunamis, typhoons, and volcanic eruptions. These are responsible for the death of countless of people, the destruction of many villages and cities, and huge expenses in relief and recovery over the course of the Philippines’ history.
Earthquakes of various magnitudes are felt daily in the Philippines. These are a result of the active convergent boundaries on both sides of the Philippines and the strike-slip Philippine Fault Zone which runs through the archipelago.
The Philippine Fault Zone is responsible for some of the largest earthquakes in the country, including the Ragay Gulf earthquake in 1973 (M 7.0), the Luzon earthquake in 1990 (M 7.7), and the Masbate earthquake in 2003 (M 6.2).
Most earthquakes are a result of the ongoing subduction in the region, including the deadly Moro Gulf earthquake of 1976 (M 8). Many are also accompanied by tsunamis, which can be severely catastrophic.
Liquefaction is responsible for the sinking of buildings and villages as much as 1m. Most earthquakes also induce landslides, which can be devastating to the nearby villages.
Volcanic activity is abundant in the Philippines (fig. 1). Ash falls, pyroclastic flows, lava flows, and lahars can severely impact or destroy nearby villages and can result in large casualties. For example, the Pinatubo eruption of 1991 erupted 3-5 km3 of lava and produced big ash falls, pyroclastic flows, and lahars. Although most people were evacuated, the event still resulted in ~700 casualties and had a large negative impact on agriculture and infrastructure. The majority of these casualties were due to roof collapse under the weight of wet ash, which has led to research regarding the strengthening of roofs near volcanoes (Spence et al., 1996). Approximately 200,000 people were left homeless and disease was common in evacuation camps. Due to the sulfur emitted into the atmosphere, Pinatubo caused a decrease in global temperature of -0.7C.
The Philippines just can’t catch a break.
Typhoons are also very common in the Philippines. The super typhoon Yolanda in 2013 is the strongest and deadliest tropical storm to hit the area. There were ~6000 deaths, entire cities were destroyed, and ~1 billion dollars were spent globally in relief and recovery efforts.
Efforts have been made to better understand and prepare for the various natural disasters that occur in the country. GPS, seismic data, and detailed mapping have been used to construct hazard maps to better assess the dangers. Also, the population is well educated concerning the risks and evacuation procedures in case a disaster arises.
References Cited:
Spence, R. J., Pomonis, A., Baxter, P. J., & AW, C. (1996). Building damage caused by the Mount Pinatubo eruption of June 15, 1991. Fire and Mud: Eruptions and Lahars of Mount Pinatubo, Philippines. University of Washington Press, Seattle, 1055-1062.
Manila Observatory. Hazards - Mapping Philippine Vulnerability to Environmental Disasters. Retrieved March 22, 2017 from vm.observatory.ph/hazard.html.