Lecture 14

Which mountains formed from ancient subduction and which mountains are formed from ongoing subduction?

Sierra Nevada and the Klamath Mountains

How did the different mountain ranges of California form?

Subduction of the Farallon Plate beneath the North American Plate, a combination of tectonic uplift and erosion, complex faulting and folding.

2022 Tonga volcano

Underwater volcano near Tonga, tsunami

What are two active volcanoes in Hawaii?

Kilauea and Mauna Loa.

Fukushima

Nuclear disaster, tsunami, 2011, meltdown of powerplant, releasing radioactive matter

Fantastic Lava Beds

series of lava tubes and associated volcanic features located in northern California, USA.

Although most eruptions in Hawaii are small, how big can they get?

volcano produce lava flows that covered over 13 square miles and added 875 acres of new land to the island of Hawaii.

How did the SNB get uplifted?

combination of tectonic processes

Batholith

large mass of intrusive igneous rock that forms beneath the Earth's surface and covers an area of at least 100 square kilometers.

What were the last two VEI-6 eruptions? How often do they occur?

1991, 2010, every decade

What was the last VEI-7 eruption? How often do they occur?

2011 every 100 years

2011 and 2022 Japan earthquakes

2011: Great East Japan Earthquake, 9.0, tsunami, 15,000 deaths 2022: 7.5, landslides, no deaths

Dacite

A fine-grained, extrusive igneous rock that is typically light gray to dark gray in color and contains high amounts of silica.

Lava Tube

A natural tunnel formed by flowing lava.

What is the tectonic setting of Japan?

the Pacific Plate, the North American Plate, and the Eurasian Plate

What may have caused the Tonga Volcano tsunami to go beyond the Pacific Ocean?

the explosion was so powerful that it sent shockwaves through the Earth's crust

Rockland Tephra

A layer of volcanic ash and pumice that was deposited during a volcanic eruption at Mount St. Helens in 1980

What part of California is especially susceptible to tsunamis?

Coast of Southern California

Nuclear Exclusion Zone

area around powerplant that was evacuated, too dangerous to live in

Why was the 2022 Tonga Volcano so explosive?

because it was a submarine eruption, meaning it occurred beneath the ocean

Baja Peninsula

long, narrow peninsula in northwestern Mexico

Sierra Nevada Batholith

massive, long-lived intrusive igneous complex located in the Sierra Nevada mountain range of California

East Pacific Rise

mid-oceanic ridge, a divergent tectonic plate boundary located along the floor of the Pacific Ocean

Escarpment

steep slope or long cliff that separates two areas of different elevations or terrain.

How and when did the granitic SNB form?

subduction. About 150 million years ago

Cocos Plate

tectonic plate located in the eastern Pacific Ocean, off the west coast of Central and South America.

Juan de Fuca Plate

tectonic plate located in the northeastern Pacific Ocean, off the coast of North America.

Lassen Peak

volcanic dome in northeastern California, USA, part of the Cascade Range.