Earthquakes & Volcanoes Study Guide PDF

# Earthquakes & Volcanoes Study Guide ## Define the following terms using our notes: * **Stress:** The force that acts on a rock to change its shape or volume * **Divergent:** Pulling the Earth's crust, gets thinner in middle * **Compression:** Squeezing rock until it folds or breaks. * **Converge...

# Earthquakes & Volcanoes Study Guide ## Define the following terms using our notes: * **Stress:** The force that acts on a rock to change its shape or volume * **Divergent:** Pulling the Earth's crust, gets thinner in middle * **Compression:** Squeezing rock until it folds or breaks. * **Convergent:** Force pushes a mass of rock in two opposite directions * **Transform:** Skip Fault! * **Fault:** Skip Fault! * **Earthquake:** Shaking and trembling from the movement of Earth's crust's plate boundaries ## Define the following terms using our notes: * **Seismic Waves:** Energy carried from the earthquake's focus * **Magnitude:** Measurement of earthquake's strength, a single number based on earthquake's size * **Tsunami:** A giant wave caused by an underwater earthquake ## What does stress do to rock? Changes it's shape and/or volume ## What are the three types of stress? 1. Tension 2. Compression 3. Shearing ## Define the following terms using our notes: * **Viscosity:** How thick a liquid is, how easily it pours * **Aa lava:** Slow-moving, cooler lava. Dries rough! * **Pahoehoe lava:** Fast-moving, hotter lava. Dries smooth or ropey! * **Pyroclastic flow:** Hot, dense mixture of ash, gas and rock fragments that come from a volcano ## Complete this sentence by filling in the blanks: The molten material in the earth is called **magma** when it is inside and called **lava** when it is outside. ## What is a volcano? Weak spot in the crust where magma has come to the surface. ## Where do volcanoes typically form? Where in the world do we see the most volcanoes? Volcanoes mostly form around tectonic plate boundaries (mostly convergent or divergent boundaries) * "In the world": Ring of Fire" ## Complete this chart. | Type of Volcano | Type of Eruption (Quiet or Explosive) | Type of Lava (Aa or Pahoehoe) | |---|---|---| | Shield Volcano | Quiet | AA and Pahoehoe | | Cinder Cone Volcano | Quiet | AA | | Composite Volcano | Explosive | AA | ## What happens at the focus? The epicenter? Focus is the point in the crust where the earthquake begins. The epicenter is on the Earth's surface directly above the focus. ## Complete this chart about the types of seismic waves. Surface waves have been done for you. | Type of Seismic Wave | Order of arrival | Movement/What it can travel through | |---|---|---| | Primary (P-waves) | 1 | Compress and expand move through: solids + liquids | | Secondary (S-waves) | 2 | Vibrates side to side and up and down move through: Solids | | Surface waves | 3 | When P/S waves hit surface move through the crust | ## What is the instrument used to record the ground movements caused by seismic waves? **Seismograph** ## Can geologist predict exactly when an earthquake will occur? Not exactly, no. Seismologists can predict where might be likely. ## What is a Tsunami? How does it happen? A giant wave caused by an underwater earthquake. ## Define the following terms using our notes: * **Volcano:** A weak spot in the crust where molten magma comes to the surface. * **Magma:** Molten mixture of rock-forming substances, gases and water from the mantle * **Lava:** Magma on the surface! * **Hot spot:** An area where lava frequently erupts at the surface. Independent of plate boundary processes.