earthquake epicenter Flashcards
are distinctive for their extremely rapid onset and tend to have impact covering large areas.
geological process
is an extreme natural events in the crust of the earth that pose a treat to life and property.
geological hazard
The crust is subjected to different types of
stress
is caused by the movement of massive, irregularly shaped slabs of rock (called tectonic plates) along plate boundaries.
stress
are regions where tectonic plates move and interact.
plate boundaries
is a planar fracture between two massive blocks of rock.
fault
The blocked located above an inclined fault plane is called a
hanging wall
is the planar flat surface of a fault across which a slip occur.
fault plane
looks like a step on Earth’s surface that is caused by a slip on the fault.
fault scarf
is the surface of a fault fracture along which the rocks have been displaced.
fault line
the block located below it is called a
foot wall
are classified according to their motion and the relative position of their fault plane
faults
form because of horizontal compressional stress, which squeezes or forces rocks together, the blocks of rocks on opposite sides of the fault move laterally (either to the left or right) This process usually occurs along transform plate boundaries
strike-slip faults
occur because of tensional stress, which forces rocks apart.This process usually occurs along divergent plate boundaries,
normal faults
form as a result of horizontal compressional stress. They are also associated with convergent plate boundaries. the hanging wall moves upward and over the footwall.
reverse faults or thrust faults
fault is considered _____ if it has moved repeatedly in the past and is likely to move again.
active
may offset or cut through entire sedimentary rock layers, This deformation of rock layers indicates continuous activity along faults.
active faults
fault is considered ____ if it has shown no signs of moving and generating earthquakes for the last hundreds of millions of years.
inactive
are confined within older sedimentary rock layers.
inactive faults
is a sudden weak or violent shaking of Earth’s surface as a result of volcanic activities or movement of tectonic plates.
earthquake
can cause massive destruction on Earth’s surface, including infrastructural damages, landslides, flashfloods, tsunamis, and soil liquefaction
earthquake
is the actual location at which the energy stored in rocks is released during an earthquake,
focus
is the point on the surface that is directly above the focus.
epicenter
The point of origin of an earthquake is called the
focus (plural foci or hypocenter)