CUASES OF EARTHQUAKE Flashcards
(15 cards)
What is the primary cause of most shallow earthquakes?
The sudden release of stress along a fault rupture (crack) in the Earth’s crust due to intense temperature and pressure changes.
How do fault zones cause earthquakes?
The movement of rocks along faults due to stress accumulation leads to sudden releases of energy, causing earthquakes.
What role do plate tectonics play in earthquakes?
The movement of tectonic plates along fault lines, especially at plate boundaries, generates earthquakes.
What types of faults are associated with earthquakes?
Normal faults (divergent boundary), strike-slip faults (transform boundary), and reverse faults (convergent boundary).
Which type of fault produces the most powerful earthquakes?
Reverse faults (convergent boundaries), where one plate is forced beneath another, causing megathrust earthquakes.
How do megathrust earthquakes occur?
They happen at subduction zones where one tectonic plate is pushed under another, releasing massive amounts of energy.
How does volcanic activity cause earthquakes?
The movement of magma within a volcano releases stress, causing volcanic earthquakes.
What is an earthquake swarm, and how is it related to volcanoes?
A series of small earthquakes occurring in a volcanic region, often indicating magma movement beneath the surface.
What are human-induced earthquakes?
Earthquakes caused by human activities such as mining, petroleum extraction, artificial lakes, and nuclear tests.
How does reservoir-induced seismicity trigger earthquakes?
The pressure from large artificial lakes alters stress along existing faults, potentially leading to earthquakes.
What is an example of reservoir-induced seismicity?
The 1967 Koynanagar earthquake in India, linked to the Koyna Dam reservoir.
How do earthquakes occur in the Himalayas?
Due to the collision of the Indian Plate and the Eurasian Plate, causing stress accumulation and fault movement.
How can human construction activities lead to earthquakes?
Large-scale infrastructure projects, including dams, tunnels, and deep drilling, can disturb fault lines and induce seismic activity.
What is the relationship between earthquakes and tsunamis?
Underwater earthquakes, especially megathrust ones, can displace ocean water and create tsunamis.
Why are earthquakes common in the Pacific Ring of Fire?
This region is highly active tectonically, with numerous subduction zones and volcanoes.
