focus is the first movement of an earthquake-underground
What is the epicenter of an earthquake
epicenter is the first movement of an earthquake on the surface
What is a seismic wave?
Seismic waves are the waves of energy caused by the sudden breaking of rock within the earth or an explosion. They are the energy that travels through the earth and is recorded on seismographs.
how did seismic waves help scientists discover the structure of the inside of the Earth?
Based on seismic data, they can figure out how much of the Earth is liquid/solid
What do seismographs measure?
measures earthquake waves
Explain how seismologist determine the distance to the epicenter of a earthquake?
The difference in arrival time between the two types of seismic wave can be used to calculate the distance of the earthquake's epicentre from the seismometer, as the further away an earthquake is, the greater the lag time between the detection of the S waves relative to the P waves.
Based on properties of the crust, and many trials, a seismologist can calculate how far away an earthquake is from a station based just on the S-P lag time.
Where does most of the damage from an earthquake occur?
most damage occurs near the epicenter
What is a volcano?
mountain that forms when magma flows through a crack onto the earth's surface
What type of plate boundary does not typically include volcanoes?
divergent
What is an active volcano?
is a volcano that has had at least one eruption during the past 10,000 years. An active volcano might be erupting or dormant
What is a dormant volcano?
is an active volcano that is not erupting, but supposed to erupt again
What is an extinct volcano?
a volcano not expected to erupt again
What is the difference between magma and lava?
magma is melted rock inside the earth and lava is melted rock that reaches the earth's surface
What type of rock forms from cooling magma or lava?
igneous rock
What causes the magma to flow upward through the Earth's crust?
mounting pressure, magma is less dense the surrounding material and hot magma rises
What is a hot spot?
is an area in the mantle from which heat rises as a thermal plume from deep in the Earth.
What is an island arc?
arc-shaped chain of volcanoes that are created through the collision of tectonic plates in an ocean setting
How did the Hawaiian islands form?
The Hawaiian Islands where formed by a hot spot occurring in the middle of the Pacific Plate
