Talk:Hotspot (geology)

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Controversy?[edit]

I'm not an expert on this subject, but hotspot theory, once seemingly unassailable, is newly controversial. See the Geological Society debate and http://www.mantleplumes.org/ . I think it would be good if the article reflected this discussion. --Rodii 23:09, 26 Dec 2004 (UTC)

mantle plumes have now been imaged all the way to core-mantle boundary. The www.mantleplume.org site is a tract against plumes by small group of dissidents; it does not represent current consensus. But it is important to distinguish between observed fact (hotspots) and presumed origin (mantle plumes, or not). In the 2 years since previous comment, plumes have become well established. Geodoc 21:24, 21 January 2007 (UTC)[reply]

Even though I am certainly no expert on this (I'm more a soft-rock geologist), having read some of literature on this, especially the excellent article by Puchkov, it seems that the basic concept of hot spots, as a model for explaining sea mount chains as the Hawai-Emporor chain, has over time been expanded to cover al sort of not clearly understood volcanic activities like unusual active mid-oceanic ridge (Iceland), lithospheric extension cracks (Eifel, Agar) and vulcanism without a clear subduction zone (Etna). So that by now almost all vulcanism that is not happening near a well defined subduction zone is by somebody at some point getting labelled as a hot-spot. In a logical critical backlash on this some people now overshoot by claiming all hot-spots are wrongly labelled, which seems to me as also jumping to conclusions. The original examples like the Hawai, Kerguelen and Louisville hotspots, moving independently of plate tectonics and plate-borders over large periods of time, still seem to have no alternative explanation. Considering this, the long list that follows is very contraproductive as it list many suspect claims of hot-spots. My suggestion would be to split this list into a short list with those undisputed long island chains that do not originated at a divergent plate margins and a long list of possible, but disputed hot-spots. In the short list only a handful would then remain, returning to the original and very convincing (and not otherwise explained) basic concept and staying clear of an ongoing scientific dispute on all the other possible, but often quite unlikely (like the Eiffel, does anybody really believe that one??) candidates.— Preceding unsigned comment added by Codiv (talk • contribs) 14:15, 11 November 2020 (UTC) The work has already been done: see this excellent article: http://www.mantleplumes.org/WebDocuments/Courtillot2003.pdf Only 7 undisputed deep mantle hotspots have been identified: Hawai, Easter Island, Louisville, Reunon, Tristan, Iceland and (much to my surprise) Afar. The list might be extended (Kerguelen, Marquesas and Galapagos are named as potentials) if more data is available, but the large majority of the hotspots named in this Wikipedia item can now be removed from this list as clearly not meeting the criteria.--Codiv (talk) 16:24, 4 May 2021 (UTC) I edited the the origin section with a explination on the primary (deep mantle) hotspots and secundary (mantle plume) hotspots. I would like to propose to use the term hotspot only to these two deeper rooted types of hotspots, not the shallow type caused by tension cracks. The latter is the cause of the diffusion of the concept and the big debate with geologist about the concept and are not real hotspots (whenever you create a path for the liquid upper mantle fraction to move up it will). But I do admit that is something like trying to get the genie back in the bottle....[reply]

Possible expansion and ammendment[edit]

It is some time now since I finished studying geology, but I believe there is some distinction made between hotpots occuring in the middle of tectonic plates (for example Hawaii), and those occuring at plate boundaries (eg. geothermal activity over the Mid-oceanic ridge in the Atlantic - Iceland being a good example). Certainly explanations as to the cause of the former are more controversial and open to debate than those in the latter, where the cause is fairly self evident. I am new to Wikipedia, so am still unclear on the etiquette of amending articles. Is there somewhere an article could be submitted for peer review before being made live? [unsigned]

Hi Zx9rsteve, jump right in :-) Of course, conside what has been done previously (not a lot here) and see the references given in the article and above. Probably best to start with a relatively small addition, see what the reaction is, and then move on to bigger edits. If you make a mistake, no problem, it can be easily undone. Go for it - I'll be watching to see what you do. This does need expansion. Also, sign your posts on talk pages with ~~~~ that's four tildes, this puts your sig and a date stamp on it. That's not for article edits though. Have fun, -Vsmith 02:06, 2 Mar 2005 (UTC)

It seems that someone's been confusing St. Helena with Mount St. Helens. It should be noted that Mt. St. Helens is obviously not a hotspot-generated volcano. I'm aware that St. Helena is an island of volcanic origin in the South Atlantic Ocean which, although extinct, may have a hotspot associated with it. St. Helena is best known as the island where Napoleon Bonaparte was exiled to after being captured by the British. -NorthernFire 16:27, 24 October 2005 (UTC)[reply]

I would recommend making hotspot volcano page part of mantle hotspot page -- essentially same thing. The Geological Society Debate was conjured up by people who contest hotspots, but as evidence accumulates - especially new seismic tomography of mantle plumes - their arguments are becoming weaker (were never that strong to begin with). Geodoc 06:38, 21 January 2007 (UTC)[reply]

hotspots[edit]

Do hotspots always make volcanoes, or do they also make pockets of magma many of kilometers under the earth's surface that do not form volcanoes? Because I know some rock formations that appear related to a hotspot about 125 million years ago, but I dont know if these are ancient volcanoes that are now vastly eroded, or they were formed when lava didn't reach the surface because they are made of gabbro and other types of rocks. Black Tusk 04:43, 05 Augest 2007 (UTC)

It seems that in the edge of Brazil and Australia the hotspot could not burn an hole through :). Quote: "We agree with Burke (1996) that hotspots are more readily seen in Africa because the exceptionally slow velocity of the African plate allows them to 'burn' through." (Plate velocities in hotspot reference frame: electronic supplement (PDF). p. 111. Retrieved 2010-04-23. {{cite book}}: Cite uses deprecated parameter |authors= (help)), (Burke, K., 1996, The African plate: South African Journal of Geology, v. 99, p. 341-409.) --Chris.urs-o (talk) 23:01, 24 April 2010 (UTC)[reply]

Plate Tectonic Processes[edit]

I removed the section about Plate Tectonic Processes theory because it was poorly written and poorly sourced to an about.com answer page. This is controversial because it's new, maybe, but it's mainstream geologists debating the issue and belongs in an article about hotspot geology. However, it should be written up in a neutral and accurate manner, not as it was. --69.226.103.13 (talk) 06:25, 2 July 2009 (UTC)[reply]

List of Hotspots[edit]

Your edit summary: "the New England hotspot lies at the African Plate not the North American Plate"

Quote: "The New England seamounts mark the most striking and best dated track in the North Atlantic. Their ages range in a linear fashion from ~100 Ma near the coast and to ~80 Ma farthest from the coast. The on-land early-extension of this track crosses the White Mountains of New Hampshire, the volcanics of the Monteregian Hills, and northwestward into the Canadian Shield west of Hudson Bay. Seaward, a less-clear continuation goes to Corner Rise. East of that, the projected age of the track is younger than the age of the seafloor on the North American side – the track then appears on the African side of the mid-ocean rift as the Great Meteor track (present-day center at 29.4°N, 29.2°W)" --Chris.urs-o (talk) 22:01, 24 April 2010 (UTC)[reply]

The New England and Great Meteor hotspots are the same thing. They are just different names that come from different features within its track. Check this out. It states: In the Atlantic, one of the longest hot spot tracks is the Great Meteor, or New England hot spot, located at 28ºW, 33ºN. BT (talk) 22:08, 24 April 2010 (UTC)[reply]

Exactly, The hotspot is on the Mid-Atlantic Ridge, and there is one chain East (New England) and one chain West (Great Meteor), as in Iceland hotspot, and Azores hotspot. See: New England Seamount chain, image:NE seamounts.jpg, image:Portion of the New England hotspot.png --Chris.urs-o (talk) 22:18, 24 April 2010 (UTC)[reply]

Yes. It has created the magma intrusions of the White Mountains in New Hampshire, the New England seamounts and seamounts in the Great Meteor seamount chain. More from here: Finally, between 100 and 80 million years ago, the hot spot formed the New England seamount chain. Bear Seamount—the oldest—formed about 100 to 103 million years ago. Moving southeasterly along the chain, the seamounts get progressively younger, with the Nashville Seamount being about 83 million years old. During the formation of the New England Seamount chain, the oceanic crust (itself only 120 to 80 million years old) pushes over the hot spot at a rate of about 4.7 cm per year. Finally, 80 million years ago, the mid-Atlantic Ridge migrated to the west over the plume. The track of this hot spot then continues on the African Plate and is found today at the Great Meteor Seamount. So what do you disagree with? There is no reason to have separate articles on the same hotspot with two different names. It can easily be New England/Great Meteor hotspot. BT (talk) 22:33, 24 April 2010 (UTC)[reply]
The Great Meteor track is NOT just on the African Plate if that is what your disagreeing with. The entire hotspot track has different names. It can be Great Meteor hotspot track or New England hotspot track. From here, it states "The 115-140 Ma Great Meteor hotspot track in eastern North America is delineated by mantle-derived igneous intrusions of various compositions. The western Quebec seismic zone (WQSZ), a 150-km wide band of mid- crustal seismicity that extends from the Adirondack Highlands into Laurentian uplands of Quebec, is located along a segment of the inferred hotspot track that lacks contemporaneous igneous intrusions. Here, it is proposed that the seismicity in western Quebec is primarily controlled by mafic intrusions that were trapped in the middle crust during the passage of North America over the hotspot. In particular, present-day seismicity may be controlled by focusing of crustal stresses due to large strength contrasts under mid-crustal conditions between mafic intrusive rocks and more felsic host rocks. In addition, the surface expression of the hotspot track is offset to the east of its predicted location, as inferred from plate reconstruction models and seismic tomographic images of the lithospheric mantle. The misalignment is anti-parallel to the direction of North American plate motion and increases with age along the track. We propose that the misalignment reflects lithospheric strain arising from traction at the base of the North American plate. If this hypothesis is correct, basal traction associated with plate motion could exert a significant role in the crustal stress field." It is clear from that paragraph that the term "Great Meteor hotspot track" is also used for the North American portion of the hotspot track. BT (talk) 23:44, 24 April 2010 (UTC)[reply]

Hello !!! Calm down. This list was a stable text from (Steinberger, Bernhard (2000). "Plumes in a convecting mantle: Models and observations for individual hotspots" (PDF). Journal of Geophysical Research. 105 (11): 11127–11152. doi:10.1029/1999JB900398. Retrieved 2008-06-15.). I just tried to add some rates, azimuths, and locations from the electronic suplement (Plate velocities in hotspot reference frame: electronic supplement (PDF). p. 111. Retrieved 2010-04-23. {{cite book}}: Cite uses deprecated parameter |authors= (help)). This is a better text than (oceanexplorer.noaa.gov - Geology). W. Jason Morgan and Jason Phipps Morgan (after 2005) named New England/Great Meteor hotspot differently, but they are the same, agree. The azimuths are always of the movement of the tectonic plates over the hotspots. This list seems ok for me now, I'll check for typos later. --Chris.urs-o (talk) 07:58, 25 April 2010 (UTC)[reply]

Alright, that's good. BT (talk) 15:12, 25 April 2010 (UTC)[reply]

Working draft[edit]

The hotspot concept seems immature. As a plate gets underneath in the subduction zone it changes its phase, as the volume of the Earth is constant, there is a pressure to get magma on the surface. Many hotspots are in one of there categories:

It seems as it is a property of the plate over the hotspot as well as a property of the hotspot itself. --Chris.urs-o (talk) 08:17, 16 May 2010 (UTC)[reply]

  • The Saint Helena hotspot is suspicious too: St. Helena Seamount Chain - Cameroon Volcanic Line. The volcanoes get younger Westwards, but so does the seafloor East of the Mid-Atlantic Ridge.
  • Don L. Anderson and Gillian Foulger are adversaries of the Mantle plume theory.
    • Quote: "In his [Anderson's] view, all non-plate boundary volcanism can be explained by shallow, plate-related stresses that fracture the lithosphere and cause volcanism along these cracks, promoted for instance by secondary, edge-driven convection in the upper-mantle." (D.L. Anderson (1998), The edges of the mantle, in: M. Gurnis et al. (eds.) The Core-Mantle Boundary Region, American geophysical Union, Washington, DC, pp. 255-271. D.L. Anderson (2000), The thermal state of the upper mantle: no role for mantle plumes, Geophys. Res. Lett. 27:3623-3626.)
  • The primary hotspots seem ok.
  • The secondary hotspots seem ok too. Superplume (Plume tectonics) determination over French Polynesia and Western Africa by Dziewonski & Woodhouse (1987) (Dziewonski, A.M.; Woodhouse, J.H. (3 April 1987). "Global images of the Earth’s interior". Science 236 (4797): 37-48)
  • A good and recent review about hotspots and this page would look better. --Chris.urs-o (talk) 13:33, 4 September 2010 (UTC)[reply]

Both Anderson and Foulger are unable to explain how if the hotspots don't exist, large masses of basalt density between 2.8 and 3.2 x 10^3 m^3 can remain, for example Iceland, Hawaii, Reunion etc; above sea level. Indeed Anderson claims that the track of the Hawaiian islands is along a fracture, but he is unable to explain why the islands are above sea level.The Geologist (talk) 16:22, 10 April 2012 (UTC)[reply]

CAMP c.200Mya --> Iceland (N) + Tristan (S) ?[edit]

Inexpertly, the major mantle plume producing the CAMP c.200 Mya, which sundered Africa & Eurasia from the Americas, has rifted both northwards, towards Iceland; and southwards, towards Tristan hotspot. Perhaps both hotspots are the northern & southern "ripples" of the ancient mantle plume head, which melted through to earth's surface, 200 Mya ? 66.235.38.214 (talk) 06:44, 1 October 2012 (UTC)[reply]

Origin of Tuamotu–Line Island chain: Easter hotspot? Not from hotspot?[edit]

In the section on postulated hotspot volcano chains, instead of the name of the hotspot of the Tuamotu–Line Island chain there was this:

Could it be a Crough hotspot, it is probably not a hotspot trail

I restored what I think was the name of the hotspot–-Easter hotspot–-based on this from the article on the Easter hotspot:

The hotspot may also be responsible for the formation of the Tuamotu Archipelago, Line Islands, and the chain of seamounts lying in between.

A footnote to that cites the same authority cited in the footnote to the item on the Tuamotu–Line Island chain in the list of postulated hotspot volcano chains in this article.

— Preceding unsigned comment added by 71.171.106.16 (talk) 16:52, 25 December 2012 (UTC)[reply]

"Unanimously"?[edit]

It says in the opening paragraph " They may be unanimously hot, and provide a great deal of molten magma." Is that accurate phraseology? Seems wrong to me, but I don't know geology much. Still seems like "uniformly" or some something would be more appropriate, but I'm not sure, because I can't even figure out for sure what the sentence is saying. How IS something "unanimously hot", if that is the correct word?.45Colt 10:11, 14 January 2015 (UTC)[reply]

Lede needs help.[edit]

I have only a lay interest in geology and volcanism, but the lede needs work, I think. 1. Hotspots are "thought to be fed by underlying mantle"??? is there any alternative to the mantle feeding them? Based on discussions on this talk page and the lede itself, there IS controversy about whether or not the mantle plume, which is well established, is anomalously hot, so it makes sense to separate those two thoughts rather than mixing them together and then proceeding to discuss why that (compound) idea may be wrong. 2. they may be on, near to, or far from plate boundaries...does that mean they can either be near or far but not "at a moderate distance"? If they aren't near to (or on) do they HAVE to be "far"? I doubt it. It is likely that the mechanism of formation (or maintenance) is DIFFERENT for those hotspots on (or near to?) plate boundaries compared to mid-plate hotspots, but simply stating they can occur "anywhere" and making that into an "they can be A, B or C" sentence structure obscures what is being said. And the statement about Hawaii and Yellowstone is USA-centric and confusing following the digression into the question of plume temperature. I propose the following:
In geology, the places known as hotspots or hot spots are volcanically active regions fed by the underlying mantle. Well known examples include Iceland, Hawaii and Yellowstone. Many hotspots occur near or on tectonic plate boundaries while others (eg. Hawaii) are far from the nearest plate edge. It is generally believed that a mantle plume, a column of anomalously hot material rising up from the core-mantle boundary, reaches the bottom of the crust (lithosphere) and spreads out, melting and mixing with some crustal rock. Some of this material will, over millions of years, push its way to the surface to be seen as volcanic activity.[1] An alternative hypothesis postulates that it is not high temperature that causes the volcanism, but lithospheric extension (cracking of the crust) that permits the passive rising of melt from shallow depths.[2][3] This hypothesis considers the term "hotspot" to be a misnomer, asserting that the mantle source beneath them is, in fact, not anomalously hot at all. 173.189.79.64 (talk) 18:14, 30 July 2015 (UTC)[reply]

Map Identification[edit]

I managed to identify each of the #s on the map with listed hotspots, with the exception of #29. It's located on the map in East Africa, probably with Afar, but it's too far south on the map to be properly in the Afar region. Anyone have better information? CFLeon (talk) 20:10, 17 August 2015 (UTC)[reply]

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Diagram colors[edit]

Can someone with information about the topic help with the caption of the initial image. It appears to say that the lithiosphere is in yellow, which my eyes take the be the middle layer, but then it says the lithiosphere is moving, but the only part of the image that appears to move is the top part (greenish-gray?). Thanks! -- Michael Scott Asato Cuthbert (talk) 23:50, 29 July 2022 (UTC)[reply]

Thanks for reporting this. I have replaced diagram "Hotspot(geology)-1.svg" with diagram "Hawaii hotspot cross-sectional diagram.jpg". I hope this is an improvement. GeoWriter (talk) 22:15, 5 August 2022 (UTC)[reply]

Raton Hotspot[edit]

The list still has the now discredited Raton Hotspot. shouldn't it be removed? Angiest (talk) 17:09, 6 January 2023 (UTC)[reply]

Possible improvement[edit]

I tend to try not to improve basic science articles so happy if my referenced corrections on mantle plume theory as I understand it from current academic reviews are improved upon in turn. Former controversy's in science tend to be resolved one way or other as additional evidence is accumulated and I have noted the difficulty others have had in integrating information that is inconsistent with the old article wording. Only addressed article because I believed a reasonably good picture (map) can save a lot of words, when dealing with complexity, and then found the words were not quite right. Some one else with better writing and knowledge skills might want to look at the second paragraph of introduction as to some readers it might look as if the two presented hypotheses are mutually exclusive and the controversy, at least with some hotspots, may be less than over a decade ago. ChaseKiwi (talk) 22:17, 21 November 2023 (UTC)[reply]

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