Eass quiz 2 quarter 3

Earthquake

the movement of the Earths plates producing strong forces that squeexe or pull the rock in the crust

shaking and trembling

what we feel during an earthquake

stress

is a force that acts on rock to change its volume or shape

shearing tension and compression

three types of stress

shrearing

causes masses of rock to slip

compression

pushes rocks together

tension

stretches the rock

fault

is a break in the crust where slabs of crust slip past each other

what creates a fault

when enough stress builds on a rock it shatters creating fualts

strike slip fault

what type of fault do shearing make

strike slip fault

when rocks on both sides of the fault line past each other with a little up and down motion creating a transform boundary

normal faults

what type of fault do tension forces create

normal fault

are at an angle so that one piece of the rock is above the fault while the other is below

foot wall

the rock below the hanging wall

hanging wall

the rock above the fault during normal faults

rift valleys

where do normal faults occur when divergence

reverse faults

what type of fault do compression forces produce

reverese fault

has the same set up as a normal fault but reversed

appalachian mountains in the east of usa

example of revverse fault

anticline

is a fold in a rock that arcs upward

syncline

a fold in a rock that arcs downward

plateaus

also called a high plain or a tableland, is an area of highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. Often one or more sides have deep hills or escarpments.

seismic wave

vibrations that travel through the earth carrying the energy released during an earthquake.

they go all directions to the focus

primary waves

aka p waves, the first waves to come

primary waves

earthquake waves that compress and expand the ground like an accordion

secondary waves

aka s waves, they shake the ground vack and fourth, they shake buildings violently

p waves

travel through liquids and solids

s waves

can only go through solids

surface waves

when s and p waves reach the top they are called what

sruface waves

move slower that p waves and s waves and produce violent ground movements
rolling like the ocean waves

seismographs

what insturment geologists use to measure the vvibrations of seismic waves

magnitude

is a measurement of earthquake strength based on seismic waves and movement along faults

mercalli scale

Developed in the twentieth

century to rate earthquakes

according to their intensity

The intensity of an

earthquake is the strength

of ground motion in a given

place

Is not a precise

measurement

richter scale

The Richter scale is a

rating of the size of

seismic waves as measured

by a particular type of

mechanical seismograph

Developed in the 1930’s

All over the world,

geologists used this for

about 50 years

Electric seismographs

eventually replaced the

mechanical ones used in

this scale

Provides accurate

measurements for small,

nearby earthquakes

Does not work for big, far

ones

the moment magnitude scale

Geologists use this scale

today

It’s a rating system that

estimates the total

energy released by an

earthquake

Can be used for any kind

of earthquakes, near or

far

Some news reports may

mention the Richter

scale, but the magnitude

number they quote is

almost always the

moment magnitude for

that earthquake

san andreas fault system

worlds most famous strike slip fault

active fault

when a fault has movesd within the last 10-00 years holocene period

intensity

based on relative ground shaking effect to people and structures reported in roman numerals

magnitude

bsed on instrumentally derived data measures the amount of total energy released at the earthquyakes point of origin
reported in arabic numerals

philippie fault zone

1300 km long fault system that stetches N-s from ilocos to eastern mindanao

left laearal strike slip

valley fault system

og the marikina fault, a pair segmented faults that form the marikina river valley and transects to eastern of metro manila
right lateral strike slip fault