Transcript Earthquake Anatomy and Tectonic Plate Boundaries

Earthquake Anatomy and
Tectonic Plate Boundaries
By:
Rachel Bitler
Marisa Congelio
Janet D’Souza
Earthquake
• A sudden motion of trembling of the Earth
• Caused by the abrupt release of energy
that is stored in rocks
Elements of an Earthquake
cse.ssl.berkeley.edu/.../ QuakesEng3.html
Seismic Waves (travel through rocks)
•
Travel inside the Earth and carry
energy from focus to surface
– P wave (like a slinkly->
moves parallel to wave
direction)
• Travels through air,
liquid, and solid
– S wave (like rope on wall->
moves perpendicular to
wave direction)
• Move only through solids
•
Radiate from the epicenter
along the Earth’s surface
– Travel more slowly than
body waves
– Two occur simultaneously:
up-and-down rolling motion
and a side-to-side vibration
earthquake.usgs.gov/ image_glossary/bodywave.html
Measurement of Seismic Waves
• Seismograph: a device that records
seismic waves
– Pen remains still as paper (and ground)
moves up and down
• Seismogram: the record of the Earth’s
vibration
www.seismo.unr.edu/.../ 100/seismic-waves.html
Earthquake Strength
• Mercalli scale measures the amount of
structural damage
• Richter scale measures the amount of
energy released during the earthquake
http://library.thinkquest.org/03oct/01428/earthquake1en.html#Intensity
Locating the Source of an
Earthquake: the time-travel curve
http://www.gly.fsu.edu/~salters/GLY1000/Chapter4/Slide20.jpg
Plate boundaries
http://www.scarborough.k12.me.us/wis/teachers/dtewhey/webquest/nature/images/Tectonic%20plate%20bou
ndaries.gify.thinkquest.org/03oct/01428/earthquake1en.html
Plate Boundaries
• Transform (San
Andreas Fault Zone)
– When plates move
horizontally past one
another
http://jove.geol.niu.edu/faculty/fischer/105_info/105_E_notes/lecture_n
otes/Plate_Tectonics/PT_part4.html
Plate Boundaries
• Convergent
(Himalayas)
– When plates move
together
http://jove.geol.niu.edu/faculty/fischer/105_info/105_E_notes/lecture_notes/Pla
te_Tectonics/PT_images/Everest.jpg
Plate Boundaries
• Divergent (East
African Rift)
– When plates
move apart
http://atlas.geo.cornell.edu/education/instructor/topography/images/east_africa_rift_lg.gif