NR 130 Exam #1

Lavas formed at continental divergent margins tend to be rhyolitic; they tend to be high in silica content because magma passes through thick continental crust on its way to the surface, melting and assimilating silica-rich crustal material.

True

Magma that reaches the Earh's surface through a volcanic vent is called Lava.

True

The perenially frozen parts of the hydrosphere are collectively referred to as the __________.

Cryosphere

P waves travel faster than s waves and p waves travel through liquid, s waves do not...T or F

True

Studies of rock paleomagnetism have revealed the ancient positions of Earth's magnetic poles.

True

The Earth is density stratified.

True

The higher the quantity of silicon dioxide in a magma the thicker the magma will be

True

The oceanic crust is made of basalt.

True

The planets formed when bits of solid matter from the solar nebula were drawn together by gravitational attraction and accretion.

True

The sun is the center of our solar system.

True

Transform fault plate margins are conservative margins, where crust is neither created nor destroyed.

True

Transform plate boundaries are not involved in the creation or deconstruction of crust rather the plates move past one another

True

Igneous rocks that cool and solidify at or near the surface are:

Volcanic Rocks

What do these things have in common: Paleomagnetism, seafloor spreading, Pangaea, Wadati-Benioff zones, transform faults, fracture zones, seamount chains, and Pacific hotspots.

They are involved with plate tectonics.

A megathrust earthquake is where a sub-ducting plate is being overridden by another plate...

True

Beneficial aspects of volcanism include the production of new volcanic rock from which rich soils develop as well as creation of new land in coastal areas.

True

Density is a measure of relative heaviness and is defined as mass per unit volume.

True

Earthquakes occur when rock masses break and slip past one another along a fault.

True

A loose assemblage of pyroclasts is known as ________.

Tephra

Oceanographers believe the breakup of Pangaea occurred about:

200 Million yrs ago

The USGS reports that an earthquake with the mag M 6.6hit Japan 27km E of Tomakomai at 2018-09-05 18:07:58 at depth of 33.4. Which number is the earthquakes focus??

33.4

Roughly how fast do most lithospheric plates move?

5 cm per year

If two oceanic plates collide at a relatively fast speed, and one is much older and cooler (therefore more dense) than the other, what will happen?

A deep trench will form.

An ________ is a volcano that has erupted within historic times.

Active volcano

Shallow earthquakes, relatively low mag, occurring in lines take place:

Along spreading ridges

The process where dissolved minerals precipitate within the pore spaces of sediment creating a glue material leading to the binding of the sediment is called?

Cementation

All the objects in the solar system orbit around Earth.

False

Along the Ring of Fire, volcanoes can occur, but not earthquakes.

False

Continental drift is a unifying theory that explains Earths topography and integrates our understanding of rock formation, mountain building, and terrain modification.

False

Earth's diameter is increasing significantly due to the generation of new ocean crust.

False

Earth's moon is a result of a comet captured within Earth's gravitational field.

False

Most seismic activity takes place along passive tectonic plate boundaries.

False

Scientific laws can never be disproven.

False

Subduction zones are areas where new seafloor is created.

False

The Hawaiian Islands were formed within the last 2 million years under a hot spot that is now inactive.

False

The age of the solar system is about 4.6 million years old.

False

The asthenosphere is cooler than the lithosphere.

False

The driving force for lithospheric plate motion is conduction to the mantle.

False

The mantle is subdivided based on its chemical composition.

False

Transform faults are never found at mid-ocean ridges.

False

True or False. At a convergent plate boundary, continental crust will subduct under oceanic crust because it is more dense.

False

We experience seasons due to the extreme changes of Earth's orbit around the Sun.

False

When a plate capped by continental crust converges with a plate capped by oceanic crust, the continental plate will undergo subduction.

False

The point where energy is first released during an earthquake, and from which seismic waves travel outward is called the ______.

Focus

The ______ is the solid Earth, composed principally of rock (by which we mean any naturall formed, nonliving, firm coherent aggregate mass of solid matter that constitutes part of a planet) and regolith (the irregular blaneket of loose, uncemented rock particles that cover the solid Earth).

Geosphere

Clastic sedimentary rocks are classified by:

Grain Size

A ______ is a point on Earth's surface where lava erupts above a plume.

Hotspot

The ________ is the totality of Earth's water, including oceans, lakes, streams, underground water, and all the snow and ice/

Hydrosphere

Molten rock that forms when temperatures rise and melting occurs in the mantle or crust is _____.

Magma

Which is the densest of earths layers

Mantle

Which of these is most abundant on or in the Earth?

Mantle material

What is one of the reasons why scientists believe the outer core is liquid

P waves and S wave shadow zones

Let's assume an earthquake occurs somewhere along the San Andreas fault. A seismograph based in Los Angeles, California monitors the earthquake. In which order will the seismic waves reach the seismograph?

P-waves followed by S-waves followed by Surface waves.

The area where we find the most active volcanoes are along the

Pacific Rim

Hazards from volcanic eruptions include:

Pyroclastic flows, Poisonous gas emissions & Volcanic mudflows

Why have no earthquakes greater than a magnitude of around 10 ever been observed?

Rocks only have enough strength to store a finite amount of elastic energy before they reach the breaking point

Elastic disturbances spreading outward from an earthquake focus are called ______.

Seismic waves

Mount Saint Helens is an example of what type of volcano?

Stratovolcano

Mount Vesuvius is an example of what type of volcano?

Stratovolcano

Gabbro is coarser than basalt because

The magma that formed the gabbro cooled slower than the basalt magma.

What does the Richter magnitude scale measure?

The magnitude of the Earth shaking during an earthquake

Why do small sediments weather faster than larger sediments?

The small sediments have more surface area for chemical reactions

Two major gases released from a volcano

Water vapor and carbon dioxide

Which scientist and explorer proposed that all earths land had been once joined into a single super-continent surrounded by an ocean

Wegener

What is obsidian?

an extrusive (volcanic) igneous rock

The Emperor Seamounts were formed:

as islands formed over a hot spot.

A "mystery" in our understanding of plate tectonics has been, until recently, the natre of the power source capable of moving the plates and the continents embedded within them. Recent evidence indicates the power source to be:

convection currents within the Earth's mantle is moving the plates.

Buoyancy is the ability of an object to float in a fluid by:

displacing a volume of water equal in weight to its own weight.

The mid-ocean ridges are:

divergent plate boundaries

New crust is being generated:

in the rift valleys of the mid-ocean ridges.

Japan is located along the Pacific Ring of Fire and experiences many earthquakes. Almost all of the earthquakes around Japan occur mostly:

on the east side of the island where the Pacific plate subducts.

A _______ is a volcano that emits both tephra and viscious lava and that builds up conical mounds.

stratovolcano

Which volcano can be described as andestic, steep side and consists of lava and tephra?

stratovolcano