Active and Inactive Faults in the Philippines
What is an active fault?
An active fault is a fracture in the Earth's crust that has moved in the last 10,000 years and is likely to move again, posing a risk of earthquakes.
What are tectonic plates?
Tectonic plates are large, rigid pieces of the Earth's lithosphere that move slowly over the semi-fluid asthenosphere beneath them.
What is the relationship between faults and earthquakes?
Faults are the locations where stress built up from tectonic plate movements is released, resulting in earthquakes.
Name one major active fault in the Philippines
Marika valley fault system, Masbate Fault, East valley fault, West valley fault
Which tectonic plate is primarily responsible for the earthquakes in the Philippines?
The Philippine Sea Plate is primarily responsible for the earthquakes in the Philippines.
How does a fault line relate to tectonic plate boundaries?
Fault lines often occur at tectonic plate boundaries, where plates interact—colliding, pulling apart, or sliding past each other—creating conditions for earthquakes.
What distinguishes an inactive fault from an active fault?
An inactive fault has not experienced movement in the last 10,000 years, while an active fault has had recent movement and poses a risk of future seismic activity.
Name one tectonic plate that interacts with the Philippine Plate.
Eurasian Plate.
Describe how stress along a fault can lead to an earthquake.
As tectonic plates move, stress builds up along a fault line due to friction. When the accumulated stress exceeds the fault's strength, it causes a sudden release of energy, resulting in an earthquake.
How often do active faults in the Philippines typically produce earthquakes?
Active faults in the Philippines can produce significant earthquakes every few decades, depending on the fault's characteristics and stress accumulation.
How do tectonic plates move?
Tectonic plates move due to convection currents in the Earth's mantle, which cause them to drift apart, collide, or slide past one another at their boundaries.
What role does the Philippine Trench play in generating earthquakes?
The Philippine Trench is a subduction zone where the Philippine Sea Plate is being forced under the Eurasian Plate, leading to significant seismic activity and the generation of earthquakes.
Why is it important to identify both active and inactive faults in the Philippines?
Identifying both active and inactive faults is crucial for assessing earthquake risk, informing land use planning, and implementing effective disaster preparedness strategies.
Explain how the movement of tectonic plates can lead to the formation of faults.
As tectonic plates move, they exert stress on the Earth's crust, causing it to deform. When the stress exceeds the strength of the rocks, it can create fractures or faults.
Explain how understanding faults and tectonic plates helps in earthquake preparedness.
Understanding faults and tectonic plates allows for better risk assessment and the development of early warning systems, infrastructure planning, and public education, ultimately enhancing community resilience to earthquakes.