Volcanos, Plates And Earthquakes

Front 1

Most Magma originates in the ____ mantle in depths between 50-250 km

Back 1

Upper

Front 2

Magmas are typically generated (3 ways)

Back 2

1. At divergent plate boundaries

2. Over subduction zones

3. At hot spots

Front 3

Most volcanoes at located over ______, although few are associated with mantle over ____

Back 3

Subduction zones; hot spots

Front 4

Fissure eruption

Back 4

Rather than from a single pipe or vent, Accounts for immense volume of volcanic rocks formed at the divergent boundaries

Front 5

The very extensive basaltic rocks of the Columbia Plateau in the western United States and of the Deccan Plateau in western India were formed by _____ eruption on continents.

Back 5

Fissure

Front 6

The very extensive basaltic rocks of the Columbia Plateau in the western United States and of the Deccan Plateau in western India were formed by _____ eruption on continents.

Back 6

Fissure

Front 7

Silica-poor, iron- and magnesium-rich magmas (mafic magmas) are low in viscosity and flow ______

Back 7

Easily

Front 8

The very extensive basaltic rocks of the Columbia Plateau in the western United States and of the Deccan Plateau in western India were formed by _____ eruption on continents.

Back 8

Fissure

Front 9

Silica-poor, iron- and magnesium-rich magmas (mafic magmas) are low in viscosity and flow ______

Back 9

Easily

Front 10

Silica-rich magmas (felsic magmas) are viscous and flow _______.

Back 10

Sluggishly

Front 11

Felsic magmas tend to trap dissolved gases, which may lead to _________ eruptions.

Back 11

Explosive

Front 12

Explosive eruptions are potentially ______ hazardous than nonexplosive (passive) eruptions.

Back 12

More

Front 13

The two main products of volcanic eruptions are ________ and ________ (fragmental volcanic material).

Back 13

Lavas and pyroclastics

Front 14

The Hawaiian Islands are composed of

Back 14

Shield volcanoes

Front 15

A _______ is a compact, steep-sided structure built of very viscous, rhyolitic and andesitic lavas emitted from a central pipe or vent.

Back 15

Volcanic dome

Front 16

A _______ has formed in the crater of Mount St. Helens left by its 1980 explosive eruption (although the Mount St. Helens volcano as a whole is a composite volcano).

Back 16

Volcanic dome

Front 17

A _______ is a symmetric, cone-shaped volcano formed from the accumulation of pyroclastics close to the volcanic vent.

Back 17

Cinder cone

Front 18

A __________ is built of interlayered lava flows and pyroclastics. They tend to have viscous, gas-charged lavas and can erupt explosively. Most of the volcanoes in the Cascade Range of the western United States are of this type.

Back 18

composite volcano (or stratovolcano)

Front 19

The primary source of hazards related to volcanic eruptions are the products of eruptions: lava flows, pyroclastic flows, lahars (volcanic mudflows), ash falls, toxic gases (mainly SO2), and phreatic eruptions.

Back 19

Everything you need to know is on the front

Front 20

The primary source of hazards related to volcanic eruptions are the products of eruptions: lava flows, pyroclastic flows, lahars (volcanic mudflows), ash falls, toxic gases (mainly SO2), and phreatic eruptions.

Back 20

Nothing on back

Front 21

A volcanic eruption can have a global impact on climate and atmospheric chemistry through the production of

Back 21

volcanic dust and/or sulfur-rich gases.

Front 22

In terms of their activity, volcanoes can be classified as

Back 22

active, dormant, or extinct.

Front 23

The likely regions of future volcanic activity can be predicted from the present-day plate tectonic map, but not the precise location or time of eruption. Selected volcanoes are routinely monitored for advance warning of volcanic activity.

Back 23

Nothing on back

Front 24

The volcanic precursors geologists look for are

Back 24

seismic activity, bulging, uplifting, or tilting of a volcano’s surface, thermal changes, and changes in the mix of released gases

Front 25

Areas in the United States vulnerable to present and future volcanic hazards include

Back 25

the Aleutian Islands of Alaska, Hawaii, the Cascade Range, the Mammoth Lakes/Long Valley area of California, and the Yellowstone National Park.