Question

geoscience
earthquakes
define:
earthquake
using elastic rebound theory, describe what triggers an earthquake.
define:
focus
epicenter:
draw:
the focus and epicenter of an earthquake along a fault
define:
aftershocks:
why are there far more earthquakes around the pacific ocean than anywhere else in the world?
why are earthquakes that occur at transform boundaries deadly?
what type of ground movement causes massive earthquakes?
describe earthquakes at divergent boundaries.

Explanation:

1. Earthquake: A sudden and violent shaking of the ground, often caused by the movement of tectonic plates along faults.
2. Elastic - rebound theory: Rocks on either side of a fault are deformed by tectonic forces. When the stress exceeds the strength of the rocks, they break and rebound to their original shape, releasing energy in the form of seismic waves, which trigger an earthquake.
3. Focus: The point within the Earth where an earthquake rupture starts.
4. Epicenter: The point on the Earth's surface directly above the focus.
5. Aftershocks: Smaller earthquakes that follow the main - shock of an earthquake. They occur as the Earth's crust adjusts to the displacement caused by the main earthquake.
6. More earthquakes around the Pacific Ocean: The Pacific Ocean is surrounded by the "Ring of Fire", a major area of tectonic plate boundaries. The subduction of oceanic plates beneath continental plates and other plate - boundary interactions create a high level of seismic activity.
7. Deadly earthquakes at transform boundaries: At transform boundaries, plates slide past each other horizontally. Sudden movement can cause large - scale ground displacement and strong shaking, which can be deadly due to the damage it causes to infrastructure and buildings.
8. Ground movement causing massive earthquakes: Large - scale movement along major faults, such as subduction - zone faults or transform faults, where there is significant stress accumulation and release, can cause massive earthquakes.
9. Earthquakes at divergent boundaries: At divergent boundaries, such as mid - ocean ridges, magma rises to create new crust. Earthquakes here are generally of lower magnitude compared to those at subduction zones, but they still occur due to the movement and fracturing of the crust as it spreads.

Answer:

1. Earthquake: A sudden shaking of the ground due to tectonic plate movement.
2. Elastic - rebound theory: Stress on rocks exceeds strength, they break and rebound, releasing seismic energy.
3. Focus: The starting point of an earthquake rupture inside the Earth.
4. Epicenter: The surface point directly above the focus.
5. Aftershocks: Smaller quakes following the main earthquake as crust adjusts.
6. More earthquakes around the Pacific Ocean: Due to the "Ring of Fire" with many tectonic plate boundaries.
7. Deadly earthquakes at transform boundaries: Sudden horizontal plate movement causes strong shaking and damage.
8. Ground movement causing massive earthquakes: Movement along major faults with high stress accumulation.
9. Earthquakes at divergent boundaries: Occur due to crust movement and fracturing as it spreads, usually of lower magnitude.