What is Volcano: Definition and 61 Discussions

A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-oceanic ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande Rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, 3,000 kilometers (1,900 mi) deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide past one another.

Large eruptions can affect atmospheric temperature as ash and droplets of sulfuric acid obscure the Sun and cool the Earth's troposphere. Historically, large volcanic eruptions have been followed by volcanic winters which have caused catastrophic famines.

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  1. Astronuc

    La Cumbre volcano eruption, Fernandina, Galapagos Islands

    https://apnews.com/article/ecuador-galapagos-volcano-599450a7a77ceb582edf1d7e5c07cb94 https://volcano.si.edu/volcano.cfm?vn=353010 https://en.wikipedia.org/wiki/La_Cumbre_(Gal%C3%A1pagos_Islands)
  2. Astronuc

    Popocatepetl volcano eruption, Mexico

    https://apnews.com/video/volcanoes-mexico-city-9d4b97b3241e4d6987670252fcd0d9de https://apnews.com/article/mexico-popocatepetl-volcano-eruption-classes-suspended-ba6cbb0309f114343b393f927b7abfca
  3. Astronuc

    What Happened to the Missing Climbers at the 2023 Merapi Eruption?

    Mount Merapi is the most active of Indonesia's 130 volcanos. https://volcano.si.edu/volcano.cfm?vn=263250 Activity had increased between October 2022 through March 2023 https://en.wikipedia.org/wiki/Mount_Merapi May 2023 -...
  4. Astronuc

    M 7.2 - 98 km S of Sand Point, Alaska; Shishaldin Volcano erupting

    https://earthquake.usgs.gov/earthquakes/eventpage/us7000kg30/executive M 7.2 - 98 km S of Sand Point, Alaska 2023-07-16 06:48:22 (UTC) 54.460°N 160.760°W 32.6 km depth There is some speculation that the Mag 7.2 earthquake may be indicative of an imminent eruption of the Shishaldin Volcano...
  5. Astronuc

    Nevado del Ruiz Volcano, Colombia - increased activity

    https://volcano.si.edu/volcano.cfm?vn=351020 The Street reported, "The last time the Nevado del Ruiz volcano was active, it erupted and killed 23,000 people in Colombia, wiping out the town of Armero in the process." Pay attention to volcanoes in the neighborhood and be prepared to...
  6. Astronuc

    Shiveluch Volcano erupts on Kamchatka peninsula

    https://apnews.com/article/russia-volcano-eruption-kamchatka-shiveluch-bd7c09dfd583d2461e537ecae113936d https://www.pbs.org/newshour/world/volcano-eruption-in-russias-kamchatka-peninsula-spews-vast-ash-clouds https://volcano.si.edu/volcano.cfm?vn=300270...
  7. Astronuc

    Three Sisters Volcano - Ongoing Magmatic Intrusion

    Three Sisters Volcano Update; Ongoing Magma Intrusion Composition Determined - the magma appears to be basaltic https://www.usgs.gov/volcanoes/three-sisters https://volcano.si.edu/volcano.cfm?vn=322070 https://en.wikipedia.org/wiki/Three_Sisters_(Oregon) From February 2022 -...
  8. Astronuc

    Alaska's Trident Volcano has increased seismic activity

    Andrew Wulfeck (FOX Weather) - Alaska officials raise alert level for volcano after increase in earthquake activity Wed, February 22, 2023 at 6:47 PM EST https://www.yahoo.com/news/alaska-officials-raise-alert-level-234711944.html https://www.avo.alaska.edu/activity/Trident.php...
  9. Astronuc

    Vanuatu - East Epi underwater volcano eruption

    https://www.cbsnews.com/news/vanuatu-underwater-volcano-erupts-east-epi-warnings/ The volcano lies 68 kilometers north of the capital Port Vila.https://volcano.si.edu/showreport.cfm?wvar=GVP.WVAR20230125-257060
  10. Isopod

    B Could anything heat back up the core of Mars?

    My understanding of why Mars lost its atmosphere was because it cooled down too much internally and that when this happened, the planet lost its magnetic field that helped protect it from solar winds (which then ended up stripping away the planets atmosphere). Is there anything that people could...
  11. Astronuc

    Hunga Tonga-Hunga Haʻapai volcano eruption, Tonga, Tsunami(s)

    Tsunami hits Tonga after giant volcano eruption (20.536°S, 175.382°W) https://www.bbc.com/news/world-asia-60007119 Tsunami waves caused by a giant underwater volcanic eruption have hit the Pacific country of Tonga. Not much in the way of an earthquake. I can only find a couple of Mag 5.0...
  12. Astronuc

    La Soufrière volcano eruption April 2021

    The government of St. Vincent and The Grenadines has been warning residents of the eastern Caribbean island of St. Vincent to be ready to evacuate the vicinity of La Soufrière volcano since about December 2020, when activity began to increase in the volcano and a new dome formed inside the...
  13. Astronuc

    Iceland earthquakes, 18000 in a week Fagradalsfjall Volcano

    SE corner of Iceland. USGS doesn't show any earthquakes during the last week. https://en.vedur.is/earthquakes-and-volcanism/earthquakes (mostly less then 2 Mag) Back in November 2019, an article on the Northern Volcanic Zone https://advances.sciencemag.org/content/5/11/eaax6642 The current...
  14. Kiwimaster76

    Plausibility of this meteor habitat?

    So in a story I'm writing humanity has found itself on another planet, its larger than Earth but less dense so that the gravity is roughly the same. There is a higher concentration of oxygen on this planet and most of it is pretty habitable. However for reasons that are too long to include say...
  15. davenn

    2018-12-22 - Volcano induced tsunami in Indonesia

    I heard a news clip whilst lying in bed watching TV but there was no mention of an eruption I rushed into look at my seismograph screen and there was no quake ... so was left shaking my head wondering what happened ... till now ... https://www.bbc.co.uk/news/amp/world-asia-46663158 The Anak...
  16. davenn

    Hawaii's Kilauea volcano eruption

    Volcano erupts near homes in Hawaii causing evacuation of residents Updated about an hour ago Fri 4 May 2018, 7:44pm http://www.abc.net.au/news/2018-05-04/volcano-in-residential-area-in-hawaii/9728316 video on that page lots of other links ...
  17. Greg Bernhardt

    Bali Mount Agung Eruption 2017

    Some experts are saying the big eruption could happen tonight! :nb):frown: http://www.cnn.com/2017/11/27/asia/bali-volcano-agung-eruption/index.html Here is a live video feed
  18. V

    Can Tungsten Be Used as a Solution for Yellowstone's Super Volcano?

    Hello, recently I noticed an article about super volcano in Yellowstone and NASA's solution by drill and pumping water in there which will be a medium for energy transfer. I hope I have read good article with good informations. A price estimation was around 3.5 mld dollars. In my country we have...
  19. D

    Volcano Question, PHYS 200 final

    Homework Statement On my physics 200 final from Athabasca A volcano shoots off a rock at a 39 degree angle, at an elevation of 1200m, and the rock has a horizontal range of 5500m. X = 5500m Y0 = 1200m Vx = Unknown Vy = Unknown V = Unknown t = Unknown a (vertical) = g = -9.8 m/s^2 Homework...
  20. Astronuc

    Is there a new volcano forming in Mexico?

    http://www.newsweek.com/mexico-volcano-burned-goats-field-636962 Residents' concerns may reflect their proximity to and history with Paricutin, which is described as a pyroclastic cone. http://volcano.si.edu/volcano.cfm?vn=341060
  21. Nik_2213

    Submarine volcanic vents and pumice rafts....

    How deep can a submarine volcanic vent be and still generate a significant pumice raft ? Sadly, Wiki is a stub, and most of the relevant literature is pay-walled. As I understand it, deep vents may generate a lot of pumice, but it never reaches the surface, just stays on the vent's flanks...
  22. Astronuc

    New Zealand's green White Island Volcano

    New Zealand http://www.wired.com/2016/05/new-zealands-white-island-volcano-rumbles-life-paints-green/ I've not heard of green ash before. Is it mineral or perhaps algae/plant matter? Ruapehu had a brief earthquake swarm last week under the volcano. The crater lake at the volcano’s summit...
  23. Astronuc

    Popocatépetl volcano erupts in Mexico - March 31, 2016

    Last week, activity at Popocatepetl began increasing. http://www.upi.com/Top_News/US/2016/03/31/Volcanic-activity-in-Mexicos-Popocatpetl-continues-to-increase/5931459434946/...
  24. Astronuc

    Alaska's Pavlof Volcano eruption - March 27, 2016

    http://finance.yahoo.com/news/volcano-erupts-southwest-alaska-sends-ash-20-000-032041050.html https://www.avo.alaska.edu/activity/Pavlof.php https://www.avo.alaska.edu/activity/report.php?id=82221&mode=hans&type=3 Some recent history - http://volcano.si.edu/volcano.cfm?vn=312030...
  25. caters

    Earthquake forming a volcano

    In my story about a planet called Kepler Bb(B flat like in music). It has 4 moons and orbits around a double binary star. In the 11th chapter I have an whole sequence of earthquakes in the same area that lasts for hours. Then after the earthquakes stop somebody checks the fault line and it is...
  26. Astronuc

    Coming to a volcano near you - maybe

    Oregon Volcano Considered for Federal Geothermal Energy Lab http://energyenvironment.pnnl.gov/highlights/highlight.asp?id=1803 So this can be applied along the Pacific coast (California, Oregon, Washington) but also places like Wyoming (think Yellowstone) as well.
  27. Astronuc

    Calbuco volcano erupts in Chile

    Calbuco volcano erupts in Chile, and nearby town evacuated Calbuco volcano erupted Wednesday for the first time in more than 42 years. Authorities ordered the evacuation of the 1,500 inhabitants of the nearby town of Ensenada, along with residents of two smaller communities. That's quite an...
  28. Astronuc

    Underneath Hawaii's Kilauea Volcano

    http://news.yahoo.com/double-trouble-found-under-hawaiis-kilauea-volcano-200943176.html It would be interesting to review the isotopics of other volcanos, which I'm sure has been done.
  29. Astronuc

    Villarrica Volcano Eruption in Chile: Thousands Evacuated

    The Villarrica volcano erupted in Chile. Villarrica volcano erupts in southern Chile, thousands flee http://news.yahoo.com/volcano-southern-chile-erupts-thousands-evacuated-112232682.html http://en.wikipedia.org/wiki/Villarrica_(volcano ) http://www.bbc.com/news/world-latin-america-31708312...
  30. anemone

    MHB A Hawaiian Volcano Is Looking for Love....

    KTbtybrQpl8 A volcano just killed us with cuteness. Pixar’s newest short film, "Lava," about a lonely volcano in the midst of a million-year search for someone to “lava,” is the most charming volcano love story we've seen since -- well, it's even better than "Joe Versus The Volcano". In...
  31. D

    Making an explosive volcano without chemicals? HELP

    Making an explosive volcano without chemicals? HELP! So here's the deal. I have to make a volcano that does not use chemicals or substances (potassium nitrate, baking soda, vinegar). It has to use mechanical parts to symbolize a volcanic eruption (ie springs for pressure). Any ideas? I have...
  32. Eagle9

    Which volcano has the greatest fire lake?

    Please tell me which active volcano on the Earth has got the largest fire lake (or moving (long) magma) like them below? And also, which fire lake has got the highest temperature? Briefly, I am looking for the largest and hottest fire lakes/places on the Earth :rolleyes:
  33. Greg Bernhardt

    Chaparrastique volcano in El Salvador blows

    El Salvador volcano erupts, prompting evacuations http://www.cnn.com/2013/12/29/world/americas/el-salvador-chaparrastique-volcano-erupts/ Video footage https://www.youtube.com/watch?v=LhPHHI_y0Q0
  34. Astronuc

    What Makes Sakurajima One of the World's Most Accessible and Active Volcanoes?

    http://news.nationalgeographic.com/news/2013/10/131010-volcano-eruption-lava-ash-sakurajima-kagoshima-japan-science/ http://www.volcano.si.edu/volcano.cfm?vn=282080 (temporarily closed due to government shutdown)
  35. T

    Volcano in mars ejects rocks. Straight line motion

    Homework Statement A certain volcano on Earth can eject rocks vertically to a maximum height . Part A: How high (in terms of H ) would these rocks go if a volcano on Mars ejected them with the same initial velocity? The acceleration due to gravity on Mars is 3.71 m/s^2 , and you can...
  36. M

    Active Volcano in Venus: Unveiling the Mystery

    Peaks of mountains in Venus are more than that on the Earth Is there any active volcano? Plz tell me about any active volcano in space
  37. M

    Toba volcano eruptions - 1.000 - 10,000 breeding pairsunb

    I was at the Smithsonian last year. They had a wonderful exhibit on human evolution. One of the displays mentioned the Toba eruption 75,000 years ago and how after that we were left with 1,000 - 10,000 human breeding pairs. How is this estimate being made? Is there also some information...
  38. M

    Falling into a Volcano: Fact or Fiction? The Truth Behind the Myth

    Recently, there has been an argument of whether or not you would sink if you were unlucky enough to fall into a volcano. The proponents of this argument focus their attention on the water/magma density difference. Since the human body consists of 60-70% water, and water is less dense than...
  39. G

    Solving for the final velocity of an object thrown off of a Martian Volcano

    The tallest volcano in the solar system is the 19 km tall Martian volcano, Olympus Mons. An astronaut drops a ball off the rim of the crater and that the free fall acceleration of the ball remains constant throughout the ball’s 19 km fall at a value of 4 m/s2. (We assume that the crater is...
  40. Evo

    What are some recent pictures of Chilean volcano eruptions?

    This is from yesterday's volcano activity. http://news.yahoo.com/nphotos/Volcano-erupts-Chile/ss/events/wl/060611chilevolcano
  41. Evo

    Have you seen the incredible pictures of Iceland's Volcano?

    These are incredible. http://www.swisseduc.ch/stromboli/perm/iceland/eyafallajokull_20100416-en.html http://www.examiner.com/x-25803-Natural-Disasters-Examiner~y2010m4d19-Italian-volcano-expert-captures-images-of-lightning-over-Icelands-Eyjafjallajokull-volcano If I can get a link to work.
  42. turbo

    Will Iceland's volcano sink the EU's economies?

    Much of the commerce in Europe is conducted via air freight, and I read in a news article today that collectively, passenger airlines are losing >$200M/day as long as European air-space is closed by volcanic ash. With all the ripple-effects that can result from this disruption of travel and...
  43. Astronuc

    Iceland Volcano - Eyjafjallajokull

    Several days ago, a volcano erupted in Iceland. EYJAFJOLL Southern Iceland 63.63°N, 19.62°W; summit elev. 1666 m http://www.volcano.si.edu/reports/usgs/index.cfm#eyjafjol background - http://www.volcano.si.edu/world/volcano.cfm?vnum=1702-02= March, 2010-...
  44. P

    Rock's Max Horizontal Distance from Volcano: 500m

    A 500m high volcano eject rocks at a speed 30 m/s.What is max horizontal distance reached by the rock?
  45. D

    What is the Launch Speed of Debris Ejected from Io's Volcanoes?

    Jupiter's moon Io has active volcanoes (in fact, it is the most volcanically active body in the solar system) that eject material as high as 500km (or even higher) above the surface. Io has a mass of 8.94×10^22 [kg] and a radius of 1815km . Ignore any variation in gravity over the 500km range of...
  46. S

    Exploring the Possibility of Volcano Shielding: Could it Work?

    Take Yellowstone for example, we do not know when it will erupt again, but we know sometime in the future that it will. We theorize that its driven from a stationary hotspot system which remains stationary as the Earth's upper crust continually slides over it until a weak spot or a spot of the...
  47. Ivan Seeking

    Is the underwater volcano near Tonga as dangerous as Surtsey?

    Video at the link. http://www.timesonline.co.uk/tol/news/environment/article5936330.ece
  48. Astronuc

    Is Redoubt Volcano About to Erupt in Alaska?

    Alaskans brace for Redoubt Volcano eruption http://news.yahoo.com/s/ap/20090130/ap_on_re_us/alaska_volcano The Alaskan and Cascade volcanos tend to erupt with ash, and in some cases, e.g. Mt. St. Helens, explode or rupture. http://www.avo.alaska.edu/activity/Redoubt.php...
  49. R

    Kinematics, volcano eruption speed problem

    A volcano launches a lava bomb straight upward with an initial speed of 28 m/s. a)Taking upward to be the positive direction, find the speed of the lava bomb 2.0 seconds after it is launched. b)Taking upward to be the positive direction, find the direction of motion of the lava bomb 2.0...
  50. lisab

    Flying through volcanic ash can be dangerous for aircraft and passengers.

    This isn't purely an Earth science question, but I don't know where else to post it. Recently, the Kasatochi volcano erupted in Alaska. It brought to mind something that happened to me a long time ago that I have always wondered about. In 1989 I was flying from Alaska to Seattle. Days...