Saturday, May 2, 2020

THE WORLD'S LARGEST CALDERAS - Calderas are large craters formed by volcanic explosions or by unsupported surface rock collapsing into empty magma chambers beneath the ground. They sometimes are referred to as supervolcanoes. One way to understand calderas is to think of them as reverse volcanoes. Volcanic eruptions often will be the cause of magma chambers being left empty and leaving the volcano above unsupported. This can cause the ground above, sometimes an entire volcano, to collapse into the empty chamber. Yellowstone Park is perhaps the most well-known caldera in the United States, drawing millions of tourists every year. According to Yellowstone's website, the supervolcano was the site of massive eruptions 2.1 million years ago, 1.2 million years ago, and 640,000 years ago. Those eruptions were, respectively, 6,000 times, 70 times, and 2,500 times more powerful than the 1980 eruption of Mount St. Helens in Washington. What today is known as Lake Toba in Indonesia is the result of perhaps the greatest volcanic eruption since the dawn of early man. Approximately 74,000 years ago, Mount Toba's eruption produced about 2,500 times more volcanic ash than Mount St. Helens. This led to a volcanic winter that had a devastating effect on the entire human population of the time. The volcanic winter lasted six years and led to a 1,000-year-long ice age, according to research, and the world population was reduced to about 10,000 adults. Research into how a massive eruption would impact the world day shows the effects to be potentially devastating.

Hawaii's Kilauea Caldera at Twilight
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The World's Largest Calderas
These Are the World's Largest Calderas
By Andrew Alden



Calderas are large craters formed by volcanic explosions or by unsupported surface rock collapsing into empty magma chambers beneath the ground.
They sometimes are referred to as supervolcanoes.
One way to understand calderas is to think of them as reverse volcanoes.
Volcanic eruptions often will be the cause of magma chambers being left empty and leaving the volcano above unsupported.
This can cause the ground above, sometimes an entire volcano, to collapse into the empty chamber.
Yellowstone Park
Yellowstone Park is perhaps the most well-known caldera in the United States, drawing millions of tourists every year.
According to Yellowstone's website, the supervolcano was the site of massive eruptions 2.1 million years ago, 1.2 million years ago, and 640,000 years ago.
Those eruptions were, respectively, 6,000 times, 70 times, and 2,500 times more powerful than the 1980 eruption of Mount St. Helens in Washington.
Explosive Force
What today is known as Lake Toba in Indonesia is the result of perhaps the greatest volcanic eruption since the dawn of early man.
Approximately 74,000 years ago, Mount Toba's eruption produced about 2,500 times more volcanic ash than Mount St. Helens. This led to a volcanic winter that had a devastating effect on the entire human population of the time.
The volcanic winter lasted six years and led to a 1,000-year-long ice age, according to research, and the world population was reduced to about 10,000 adults.
Potential Modern Impact
Research into how a massive eruption would impact the world day shows the effects to be potentially devastating. 
One study focusing on Yellowstone suggests another eruption comparable in size to the three biggest ones of the past 2.1 million years would kill 87,000 people instantly. The volume of ash would be enough to collapse rooftops in states surrounding the park.
Everything within about 60 miles would be destroyed, most of the western United States would be covered in about 4 feet of ash, and an ash cloud would spread across the entire planet, casting it in shadow for days.
The impact on vegetation could lead to food shortages across the planet.
Visiting the Largest Calderas on the Planet
Yellowstone is just one of many calderas throughout the world. Like Yellowstone, many of the others can be interesting and fascinating places to visit and to study.
Below is a list of the world's largest calderas:
Caldera name
Country
Location
Size
(km)
Most
recent
eruption
La Pacana
Chile
23.10 S
67.25 W
60 x 35
Pliocene
Pastos
Grandes
Bolivia
21.45 S
67.51 W
50 x 40
8.3 Ma
Kari Kari
Bolivia
19.43 S
65.38 W
30
Unknown
Cerro Galan
Argentina
25.57 S
65.57 W
32
2.5 Ma
Awasa
Ethiopia
7.18 N
38.48 E
40 x 30
Unknown
Toba
Indonesia
2.60 N
98.80 E
100 x 35
74 ka
Tondano
Indonesia
1.25 N
124.85 E
30 x 20
Quaternary
Maroa/
Whakamaru
New
Zealand
38.55 S
176.05 E
40 x 30
500 ka
Taupo
New
Zealand
38.78 S
176.12 E
35
1,800 yr
Yellowstone
USA-WY
44.58 N
110.53 W
85 x 45
630 ka
La Garita
USA-CO
37.85 N
106.93 W
75 x 35
27.8 Ma
Emory
USA-NM
32.8 N
107.7 W
55 x 25
33 Ma
Bursum
USA-NM
33.3 N
108.5 W
40 x 30
28-29 Ma
Longridge
(McDermitt)
USA-OR
42.0 N
117.7 W
33
~16 Ma
Socorro
USA-NM
33.96 N
107.10 W
35 x 25
33 Ma
Timber
Mountain
USA-NV
37 N
116.5 W
30 x 25
11.6 Ma
Chinati
Mountains
USA-TX
29.9 N
104.5 W
30 x 20
32-33 Ma
Long Valley
USA-CA
37.70 N
118.87 W
32 x 17
50 ka
greater Maly
Semiachik/Pirog
Russia
54.11 N
159.65 E
50
~50 ka
greater Bolshoi
Semiachik
Russia
54.5 N
160.00 E
48 x 40
~50 ka
greater
Ichinsky
Russia
55.7 N
157.75 E
44 x 40
~50 ka
greater
Pauzhetka
Russia
51 N
157 E
~40
300 ka
greater
Ksudach
Russia
51.8 N
157.54 E
~35
~50 ka
Andrew Alden
Geology Expert
Education
B.A., Earth Sciences, University of New Hampshire
Introduction
Professional geologist, writer, photographer, and geological tour guide
Thirty-seven years of experience writing about geological subjects
Six years as a research guide with U.S. Geological Survey (USGS)
Experience
Andrew Alden is a former writer for ThoughtCo who contributed hundreds of articles for more than 17 years. Andrew works as a geologist, writer, editor, and photographer. He has written on geological subjects since 1981 and participates actively in his field. For example, Andrew spent six years as a research guide with the U.S. Geological Survey, leading excursions on both land land and at sea. And since 1992, he has hosted the earthquakes conference for the online discussion platform, The Well, which began as a dialogue between the writers and readers of the Whole Earth Review. 
In addition, Andrew is a longtime member of the member of the Geological Society of America — an international society that serves members in academia, government, and industry; and the American Geophysical Union — a community of earth and space scientists that advances the power of science to ensure a sustainable future.
Andrew lives in Oakland, California; and though he writes about the whole planet and beyond, Andrew finds his own city full of interest too and blogs about its geology
Education
Andrew Alden holds a bachelor's (B.A.) degree in Earth Science from the University of New Hampshire, College of Engineering and Physical Sciences, in Durham, N.H.
Awards and Publications
Andrew Alden on Earthquakes (The Well Group, Inc., 2011)
Assessment of River — Floodplain Aquifer Interactions (Environmental and Engineering Geoscience, 1997)
Andrew Alden on Hosting (The Well Group, Inc., 1995)
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Hawaii's Kilauea Caldera at Twilight

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