Earthquakes: Waves, Faults and Folds

By: Marg Dyan D. FernandezPrincess Amaryah P. EjaresNatSci1-A7

Earthquake A shaking, trembling, or concussion of

the earth, due to subterranean causes, often accompanied by a rumbling noise. The wave of shock sometimes traverses half a hemisphere, destroying cities and many thousand lives

Types: Foreshock Aftershock Blind thrust Interplate Intraplate

Wave a disturbance (an oscillation) that

travels through space in time, accompanied by the transfer of energy.

Waves travel and the wave motion transfers energy from one point to another, often with no permanent displacement of the particles of the medium—that is, with little or no associated mass transport

http://en.wikipedia.org/wiki/File:Wave_packet.svg

Faults A planar fracture or discontinuity in a

volume of rock across which there has been significant displacement along the fractures as a result of earth movement.

Faultline The surface trace of a fault

Folds: When one or stack of originally flat and

planar surfaces, such as sedimentary strata, are bent or curved as a result of permanent deformation.

Types: Anticline – linear strata normally dip

away from axial center, oldest strata in center

Syncline- linear strata normally dip toward axial center, youngest strata in center

Antiform – linear strata dip away from axial centre, age unknown or inverted

Synform- linear, strata dip toward axial centre, age unknown or inverted.

Dome- nonlinear, strata dip away from center in all directions, oldest strata in center

Basin- nonlinear- strata dip toward center in all direction between horizontal layers on each side.