Thursday, March 31, 2011

Northridge Earthquake



I learned that the magnitude of the Northridge Earthquake was 6.7 and earthquake caused very large ground motions with peak accelerations of 0.5 to 1.0 g in the Northridge area.

Friday, March 25, 2011

Wednesday, March 9, 2011

Earthquake Hazards in California

 




I learned Earthquake shaking hazards are calculated by projecting earthquake rates based on earthquake history and fault slip rates, the same data used for calculating earthquake probabilities.

Tuesday, March 1, 2011

Seismic Waves


I learned that vibration generated by an earthquake , explosion, or similar energetic source and propagated within the Earth or along its surface. Earthquakes generate four principal types of elastic waves; two, known as body waves , travel within the Earth, whereas the other two, called surface waves , travel.

Friday, February 25, 2011

Batholith






I learned that a batholith is a main magma chamber and it ranges from hundreds to thousands of cubic kilometers across km beneath earths surface.

Thursday, February 17, 2011

strata vs. shield volcanoes



Shield Volcano is made up of basalt like Hawaii. It's slopes are made by liquid basalt lava that pushes up from a vent under the ground.




More than one kind of magma builds up in Stratovolcanoes. They are basalt, andesite, dacite, and rhyolite magma.

Tuesday, February 8, 2011

Gulf Current




I learned a current of warm water that keeps Western Europe warm is the Gulf Stream and 71% of the world is covered by Ocean Water.

Wednesday, February 2, 2011

Plate Tectonics


I learned that ages of ocean crust and the thicknesses of ocean-floor sediment increase with distance from an ocean ridge and the three types of convergent boundaries are oceanic-oceanic, oceanic continental and continental-continental.

Friday, January 28, 2011

Oceans




I learned that the underwater mountain chains that form when plates move apart is a mid-ocean ridge and that underwater volcanic cones are seamounts.

Wednesday, January 19, 2011

Water Cycle



The Water Cycle
Water on Earth is always changing. Its repeating changes make a cycle. As water goes through its cycle, it can be a solid (ice), a liquid (water), or a gas (water vapor). Ice can change to become water or water vapor. Water can change to become ice or water vapor. Water vapor can change to become ice or water.