| A | B |
|---|
| What is the major cause of earthquakes? | plate movement |
| 80% occur at the ______? | Pacific Ring of Fire |
| What are the three types of seismic waves? | primary, secondary, and surface |
| What is the point underground where the rocks actually move? | focus |
| It takes three seismograph stations in three diff. cities to locate a(n) _____? | epicenter |
| Which waves travel the fastest? | primary |
| Which waves cannot travel through liquid? | secondary |
| Which waves cause the most damage? | surface |
| The surface waves occur only near the ______? | epicenter |
| What is tension? | the force caused by pulling in opposite directions and causes normal faults to occur |
| What occurs in the Himalayas where two plates are colliding? | reverse faults |
| What is a seismograph? | An instrument that measures the magnitude of an earthquake |
| What scale rates the damage caused by earthquakes? | Mercalli |
| Where in S.C. did a high intensity earthquake occur? | Charleston |
| Where in the U.S. are most earthquakes concentrated? | San Andreas |
| What do seismic waves do when they enter and exit different layers of earth? | speed up |
| What is the Mohoe discontinuity? | the imaginary between the crust and the upper mantle |
| Rocks break when they reach what? | elastic limit |
| What is shear? | the type of force exerted on rocks at the San Andreas Fault |
| What is a tsunami? | a large ocean wave caused by earthquakes near the ocean floor |
| Which seismic wave moves rocks up and down? | secondary |
| Which seismic wave moves rocks side to side? | primary |
| Which seismic wave moves rocks up, down, & side to side? | surface |
| Which volcanoes have the most violent eruption? | composite |
| Which volcanoe have alternating layers of ash and lava? | composite |
| Which magma is very high in silica? | granitic |
| Which magma is very low in silica? | basalt |
| What are the three deadly gases that can be released from a crater or vent? | sulfur, chlorine, and CO2 |
| What are lava bombs? | the largest airborne particles thrown from a volcano |
| What causes the small earthquakes around an active volcano? | magma moving |
| If a volcano is not active, but has been active in the past it is said to be _______? | dormant |
| What are 5 ways that scientist monitor volcanoes? | gases, years between eruptions, age, shape, acidity of water |
| What is an island chain made of shield volcanoes? | Hawaii |
| Where do shield volcanoes form at? | a hotspot |
| The lava at a hotspot is very ____ in silica. | low |
| The eruptions at hotspots are fairly _____. | calm |
| ________ is an active volcano in the Cascade Range | St. Helens |
| St. Helens is caused by a ________ where an oceanic plate is being pushed under North America. | subduction zone |
| The magma/lava at St. Helens is very _____. | high |
| The eruptions at St. Helens aer very ______. | violent |
| What is a cinder cone? | a small, steep volcano |
| What are cinder cones made of? | tephra |
| What is a lahara? | a volcanic mudflow made of ash, dirt, and meltwater |
| What is pahoehoe? | a type of lava with a thickness like honey |
| What is a pyroclastic? | a cloud made of molten ash that races down a volcanoes slope at 150 miles per hour |
| What is thick and moves very slowly, and sometimes called clinkery | Aa |
| What is ash? | the smallest airborne particle thrown from a volcano |
