Did you know we have earthquakes in Swain County?

This is a map of the major oceanic spreading centers.

The mountains along this section were created by three plates colliding together.

Tension

Shearing

Earthquakes create seismic waves which shake the ground as they pass just like waves of water moving across the ocean.

Types of Seismic Waves Earthquakes generate three major types of seismic waves P, for "Primary" S, for "Secondary" waves L, for “Long” waves

A drop disturbs the flat surface of the water and creates waves that travel outward in all directions from the disturbance. Earthquake waves travel the same way

P Waves - Primary The P waves move in a compressional motion similar to the motion of a slinky Move the fastest and are the first recorded by a seismographic Can travel through liquids, gases and solids

S Waves - Secondary S waves move in a shear motion perpendicular to the direction the wave is traveling. Secondary Waves are the second to be recorded by a seismograph, Can only travel through solid materials P and S waves

L Waves – Long Waves or Surface Waves Surface or L waves occur only in the earth's crust and cause the most damage travel along the surface of the earth from the point directly above the quake or epicenter Slowest moving waves, last to be recorded by a seismograph. wave visualization

Shadow ZonesShadow Zones are places that do not receive any earthquake waves The shadow zone is the area of the earth from angular distances of 104 to 140 degrees from a given earthquake that does not receive any direct P waves. The shadow zone results from S waves being stopped entirely by the liquid core and P waves being bent (refracted) by the liquid core.

An earthquake is a sudden shaking of the ground. They generate seismic waves which can be recorded on a sensitive instrument called a seismograph.

Advances in seismograph technology have increased our understanding of both earthquakes and the Earth itself.

Focus Epicenter wave visualization 2

Faulting and Folding

Folding

Pressure:

Rock Type:

There are three general types of foldsSynclines Anticlines Anticlines Monoclines Monoclines

Faulting

Hanging Wall and Footwall

Hanging Wall

Footwall

http//youtu.be/tJDnfT1pqhQ

Thrust faultsThrust faults: this is when the hanging wall is actually forced up onto and over the foot wall due to compression in the rock.

Igneous intrusion D is younger than strata layers A, B, and C, but not younger than fault line E

Earthquake visualization risk visualization

Scientists are trying to make more accurate predictions by detecting changes in the earth’s crust. Faults have been located and mapped Instruments placed along faults measure small changes in rock movement.

Indonesia Earthquake and Tsunami