Vocabulary
What is tephra?
Ash and small rocks (aka, tephra).
How do we measure earthquakes?
Seismometers
How old do scientists think that the Earth is?
4.6 billion years
List the 4 different types of convergent plate interactions.
Shield Volcano
A volcano that is formed by layers and layers of lava.
What is the closest stratovolcano to us here in Anchorage?
Mt Spurr
What is the second type of seismic wave that is sent out by an earthquake?
S-waves or secondary waves.
In what time period were most dinosaurs around?
Jurassic, Triassic, and Cretacious
What is different about the outer core?
It is liquid and spinning quickly.
What is the mantle?
The biggest, middle layer of the Earth.
What causes ground deformation of a volcano?
Magma moving in the magma chamber.
Why do earthquakes tend to happen in Alaska?
We are on the edge of two tectonic plates moving towards each other.
What are some good index fossils?
Ammonites, Trilobites, Crinoid, Brachiopod
What is the difference between oceanic crust and continental crust?
Oceanic Crust is more dense and so will subduct underneath continental crust.
What is an index fossil?
A fossil that is used to date the sedimentary rock around it.
List 3 ways scientists monitor volcanoes.
GPS, seismometers, visual/pictures, gas sampling, flights, tiltmeters
When did the biggest earthquake happen in North America?
1964
What is the current era?
Cenozoic Era
What is a spreading center?
On a divergent boundary, typically in the ocean, new crust is being formed by underwater eruptions.
What is a Divergent Plate Boundary?
Where two tectonic plates are moving apart from each other.
T/F: We have all three types of volcanoes here in Alaska.
True
What is a seismic shadow zone?
What are the 5 increments of time in the Geologic Time Scale?
Eons, Eras, Epochs, Periods, Ages
How do Convection Currents impact how tectonic plates move?