Earthquakes and Volcanoes. Bell Work 12/9/10. Turn on computers Notes today. Rest of this week and next. Wednesday (12-8-10)- Slides 1-6 and handout science fair packets and talk about it Thursday (12-9-10) - Complete slides 7-12 and start B/F/F scenario
Turn on computers
Earthquake – is the shaking and trembling that results from the sudden movement of part of the Earth’s crust.
Tsunamis – A giant sea wave produced by an earthquake.
Focus – The point beneath the Earth’s surface where the rocks break and move, the underground origin of the earthquake.
Epicenter – The point directly above the focus, on the earth’s surface where the origin of an earthquake is above ground.
1. Primary waves (P-waves) – arrive at a given point before any other type of seismic wave. Will pass through solid, liquid and gas.(fastest of the three)
2. Secondary Waves (S-waves) – arrive at a given point after the P wave. (second fastest) Will only travel thru solids. Will NOT pass through liquids and gases thus creating a shadow zone.
Seismograph – is an instrument that detects and measures seismic waves.
Seismogram – is the record of waves. (paper record)
Seismologists – scientists who study earthquakes.
Richter scale – calculation of the strength or magnitude of an earthquake.
For every 1 point rise 30 times the energy is released.
Magnitude - Height of a line traced on a seismogram.
Earthquake preparedness – Tie down heavy objects, take objects off of high shelves. Build on an earthquake proof foundation. Have a plan and emergency items.
Volcano – the place in the Earth’s surface through which magma and other materials reach the surface.
Magma – rock that exists as a hot liquid deep within the earth.
Lava – is magma that reaches the Earth’s surface.
Crater – Steep walled depression around a volcano’s vent.
Hot Spot – Hot rock that is a result of unusually hot areas in the mantle and core where volcanoes form on the Earth’s surface. Hawaii is the result of a hot spot.
Composite Volcanoes – are made of alternating layers of rock particles and lava. Violent eruptions followed by quiet lava flows are the reasoning for the alternating layers.
Andesitic - is a combination of both granitic and basaltic lava flows (quieter than granitic but more violent than basaltic).
Gas filled lava – This lava cools to form hole filled rock that has the appearance of a sponge or loaf of bread. This rock type is typically light in weight. Pumice and scoria are examples of this type of igneous rock.
Volcanic Dust – Is fragments of rock that are blown into the air during a volcanic eruption. (very small particles)
Volcanic Ash – Is particles blown into the air from a volcano that are bigger than volcanic dust yet smaller than anything else.
Extinct – Not known to have erupted in recorded time. Usually weathered down to base.
Active – well, it is active in modern time.
Ring of fire – is the zone of active earthquakes and volcanoes due to very active tectonic plate movement.