Earth and Space Science Exam #2 Study Guide

What plate boundaries create composite volcanoes?

Oceanic continental plate

What is the process of separation based on density?

Differentiation

What are three examples of isostasy?

An iceberg, a floating dock, a boat in the water

True or False: Water boiling on the stove is an example of isostasy

False

Oceanic crust is ___________________ than continental crust.

Younger, thinner and more dense

What is the theory describing the large scale motion of the Earth's lithosphere?

Plate tectonics

What are three materials that convection currents can be found in?

Water, air, mantle

At what type of plate boundary would you find a trench?

Convergent

What are three occurrences that are associated with a divergent boundary?

Mid-ocean ridge, seafloor spreading, rift valley

True or False: Subduction zones are not associated with a divergent boundary

True

Plates slide past each other at ______________________.

Transform boundaries

The Hawaiian Islands formed over a ____________________.

Hot spot

What is the study, mapping and measurement of seafloor topography called?

Bathymetry

What simple tool is used to take depth soundings?

Lead Line

What shows the statistical distribution of elevations and depths across the entire planet's surface?

Hypsographic curve

_________________ margins are not near a plate boundary and have wider shelves.

Passive

The _________________ is geologically part of the continent.

Continental shelf

What are the flattest, smoothest and least explored regions on Earth?

Abyssal plains

Trenches are associated with ________________________.

Volcanic arcs

Mid-ocean ridges may contain _________________________.

Seamounts, Hydrothermal vents, pillow lava

Fracture zones are _____________________ because both plate segments are going in the same direction.

seismically active

What is the the continental marked by that is carved into the slope by turbidity currents?

Submarine canyons

Where are the turbidite deposits and deep-sea fans located?

Continental rise

True or False: A volcano with a repose period of 10,000 years is more explosive than one with a 1,000-year repose period.

False

About _____________ volcanoes are currently active.

500

What invention is the reason that starvation is no longer a primary cause of death from volcanic eruptions?

Transportation

True or False: If a volcano has a higher silica content, the lava it produces flows easier.

False

What causes explosive eruptions?

Buildup of gases

Which type of lava is quick-cooling, thick, rough and jagged?

Aa

Composite volcanoes are made of ____________.

Alternating layers of lava and pyroclastic

What type of fault is associated with divergent boundaries?

Normal fault

What is the point of an earthquake's origin inside the Earth?

Focus

_________________ are tremors that result from the settling of the fault.

Aftershocks

A 4.0 earthquake is ________ times stronger than a 3.0.

10

What instrument is used to detect and measure earthquakes?

Seismometer

What does calculating the difference in the arrival time of P and S waves help us determine?

Distance to the epicenter

Which magnitude scale measures how people react to an earthquake?

Mercalli Scale

Primary waves...

shake the ground in the direction the wave is traveling and are the first to arrive.

_____________ is an earthquake effect where saturated soils become unstable.

Liquefaction

True or false: A tsunami along the coast has a longer wavelength than a tsunami in the deep ocean.

False

________________ is the time interval between successive eruptions.

Repose period

What are three factors that control volcano formation and the type of eruption?

temperature, gas content, composition

Materials that have been ejected into the atmosphere by volcanic activity are called _____________________.

pyroclastics

Pyroclastic flows are the most _____________ of all volcanic phenomena.

Deadly

What type of volcano is built almost entirely of fluid lava flows?

Shield

What are geothermal features that periodically erupt due to superheated water getting trapped behind constrictions?

Geysers