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.