EVSC101 chapter 7

EVSC101 chapter 7 - EVSC- Exam 2 study guide I. Earthquakes...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
EVSC- Exam 2 study guide I. Earthquakes (chapter 7) a. Class notes: i. -Charles Richter- antiquated buildings do harm ii. relative movement of the plates at their boundaries result in bending and breaking of solid rock (relative plate speed is measured in centimeters per year. iii. rocks are deformed by folding or faulting where they are subjected to different kinds of tectonic forces 1. convergent- pushing up against continental margin- a. lateral forces compressive forces make rock fold. If it breaks (one rock on top of the other)---- it results in a fault b. movement of one rock on top of another is the cause of earthquakes. 2. Divergent - tension pulling plates apart a. - thins crust until it has to break b. Results in the lengthening of earth’s crust 3. Transform - shearing a. Sideways twisting force until faulting occurs iv. Folds in originally horizontal rock layers are the result of compressive tectonic stresses v. Rocks break, not bend, movements along fractures relieves the stress of the directed pressure on a section of Earth’s crust. vi. Fault plane- plane of fracture vii.The snapping back of plates results in earthquakes
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
viii. Focus- point at which the slip initiates ix. Epicenter- point on the surface directly over the focus ( part of the earthquake that is reported. x. Fault scarp is an abrupt, steep slope separating two relatively level areas. Fault scarps only form if the earthquake reaches all the way to the surface xi. Deep focus earthquakes coincide with convergent boundaries. Earthquakes occur along the inclined plane of the subducted plate. xii.Harbor at Napier, New Zealand- Feb. 3, 1931. . 7.9 magnitude lasting 2.5 minutes, 258 people died because the harbor was raised by 7 feet.--- VERY rare that someone dies. Convergent quake xiii. Shallow-focus earthquakes are typical of divergent plate boundaries and transform faults. xiv.Transform faults develop where plates slip past each other at approximately right angles to their divergent boundaries in order to accommodate differential rates of spreading. xv. San Andreas Fault- streams draining from the higher elevated North American plate (east) onto the lower pacific plate (west) 1. Plates move past each other in opposite directions- creeks crossing the fault have been offset- gives us the magnitude of slip xvi. Magnitude- given in numbers from 1-10 (richter scale), scale is logarithmis. 1. ****** two earthquakes that differ in amplitude of ground motion by a factor of 10 and energy release by a factor of 32, differ in magnitude by 1. xvii. Earthquakes worldwide on a given year= 3,000,000 1. Actually detected= 20,000 year
Background image of page 2
2. Death= 20,000 (varies) xviii. The intensity is the most useful information about where the greatest damage to structures, and therefore impact on human life, is concentrated. 1.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 10

EVSC101 chapter 7 - EVSC- Exam 2 study guide I. Earthquakes...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online