Three Sisters Volcano Magmatic Intrusion

The video discusses the Three Sisters volcano in Oregon, focusing on the ongoing magmatic intrusion beneath it. The intrusion, detected since 1995, has caused minor unrest, including uplift and low-magnitude earthquakes. The magma is basaltic, suggesting a less explosive potential eruption. The volcano remains at a green alert level, indicating low immediate risk. Historical eruptions and the composition of the volcano are also covered, highlighting the presence of basalt, rhyolite, and dacite. The video concludes with a hazard map and reassures that an eruption is unlikely soon.

What recent discovery was made about the Three Sisters volcano?

• The number of eruptions in the last century

• The age of the volcano

• The composition of the magma beneath it

• The height of the volcano

What has been the effect of the magmatic intrusion at the Three Sisters volcano?

• Increased volcanic eruptions

• Formation of a new crater

• Uplift and low magnitude earthquakes

• Decrease in volcanic activity

How long has the magmatic intrusion been ongoing at the Three Sisters volcano?

• Since 1995

• Since 2000

• Since 1985

• Since 2010

What type of eruptions have occurred at the Three Sisters volcano in the past 10,000 years?

• Highly explosive eruptions from the summits

• Continuous lava flows from the base

• Moderately explosive eruptions producing cinder cones

• No eruptions have occurred

Which types of lava are the Three Sisters stratovolcanoes composed of?

• Andesite and dacite

• Pumice and tuff

• Rhyolite and obsidian

• Basalt and granite

What is the composition of the ongoing magmatic intrusion beneath the Three Sisters volcano?

• Basalt

• Dacite

• Rhyolite

• Granite

Why is the current magmatic intrusion considered less concerning?

• It is at a shallow depth

• It has already erupted

• It is composed of rhyolite

• It is basaltic and has minimal seismic activity

What is the current alert level of the Three Sisters volcano?

• Orange

• Yellow

• Green

• Red

What does the hazard map of the Three Sisters volcano display?

• The depth of the magma chamber

• The expected radius of volcanic hazards

• The history of past eruptions

• The exact location of future eruptions

What is the likelihood of an eruption at the Three Sisters volcano in the near future?

• Unlikely

• Likely

• Certain

• Very likely