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A little cringe... as someone who listens to geology podcasts, the idea of "hot spots" apparently doesn't hold much scientific scrutiny any more. This will prob

A little cringe... as someone who listens to geology podcasts, the idea of "hot spots" apparently doesn't hold much scientific scrutiny any more. This will probably take another decade to be phased out since everyone is taught in school Hawaii etc. are created by hot spots/mantle plumes. The newer explanation is actually simpler and explained by plate tectonics... deep extensional faults in the middle of plates (generally at stress change boundaries, since the plates are stressed differently at opposite margins) is sufficient to get these island-forming magma extrusions. EDIT - by request, my favorite geo podcast is Oliver Strimpel's Geology Bites.

sxv 5y ago
Off-topic, but can you recommend some geology podcasts, either science-centric or for the layperson?
- mutagen 5y ago
  An acquaintance of mine is a big fan of Nick Zenter's videos on Youtube. https://www.youtube.com/user/GeologyNick https://www.youtube.com/user/GeologyNick
- mikelockz 5y ago
  I liked Dick Gibson's History of Earth podcast https://historyoftheearthcalendar.blogspot.com/ https://historyoftheearthcalendar.blogspot.com/ And Dr. Christian Shorey Earth and Environmental Systems podcast https://geology.mines.edu/sygn101-podcasts/ https://geology.mines.edu/sygn101-podcasts/
rich_sasha 5y ago
Interesting, could you point at some further reading? My wife studied volcanology, I helped her with some of the maths involved, seems like a fascinating subject!
- eesmith 5y ago
  I'm also curious about this change in terminology. I used Google Scholar for papers in 2021 and easily found geology papers using the term "hot spot". > Hot spots are the surface expression of plumes of hotter and lighter material upwelling from the Earth’s mantle. The current number of hot spots is estimated to range between 45 and 70: these are mostly in intraplate settings, especially on oceanic lithosphere, and along divergent plate boundaries. - https://link.springer.com/chapter/10.1007/978-3-030-65968-4_13 https://link.springer.com/chapter/10.1007/978-3-030-65968-4_... > Regardless of the nature and origin of hot spots and whether they are fixed or mobile, the fact remains that there is a major thermal anomaly under Iceland, commonly referred to as the “Icelandic hot spot”. - https://onlinelibrary.wiley.com/doi/abs/10.1002/9781119850922.ch2 https://onlinelibrary.wiley.com/doi/abs/10.1002/978111985092... > The Cape Verde Islands are considered as the surface expression of a mantle plume at 500–800 km west of the African continental margin. The spatial and chronological evolution of volcanic activity, from East to West, is consistent with the slow progression of the African plate over the hotspot since at least the Oligocene - https://www.nature.com/articles/s41598-021-96897-1 https://www.nature.com/articles/s41598-021-96897-1 > Mantle plumes were discovered almost 50 years ago by Morgan and Wilson. They are long-lived (up to ~100 Ma) jets of hot matter rising from the bottom of the mantle and burning through moving lithospheric plates and continents in hot spots, forming large magmatic provinces. - https://link.springer.com/article/10.1134/S1028334X21090191 https://link.springer.com/article/10.1134/S1028334X21090191 To be clear, this only shows that some geologists use the term. It may be a small and decreasing minority found only because that's the specific search term I was looking for.
njarboe 5y ago
The hot spot versus plate movement/stress debate has been going on for many decades. Some hot spots are likely mostly caused by tectonic stress differences, but others seem likely to be from plumes. Scientists get published for novelty more than correctness, so if a theory is around for awhile and another can explain something in a different way, it is more likely to be published. Isotopic chemical data does suggest some volcanic sources come from the mantle (deep in the earth) where others are more likely crustal melting, which can be caused by tectonic decompression. I would be interested if you have a source of a review paper on the current ideas on hot spots, if you have it.

sxv 5y ago

Off-topic, but can you recommend some geology podcasts, either science-centric or for the layperson?

mutagen 5y ago
An acquaintance of mine is a big fan of Nick Zenter's videos on Youtube. https://www.youtube.com/user/GeologyNick https://www.youtube.com/user/GeologyNick
mikelockz 5y ago
I liked Dick Gibson's History of Earth podcast https://historyoftheearthcalendar.blogspot.com/ https://historyoftheearthcalendar.blogspot.com/ And Dr. Christian Shorey Earth and Environmental Systems podcast https://geology.mines.edu/sygn101-podcasts/ https://geology.mines.edu/sygn101-podcasts/

rich_sasha 5y ago

Interesting, could you point at some further reading? My wife studied volcanology, I helped her with some of the maths involved, seems like a fascinating subject!

eesmith 5y ago
I'm also curious about this change in terminology. I used Google Scholar for papers in 2021 and easily found geology papers using the term "hot spot". > Hot spots are the surface expression of plumes of hotter and lighter material upwelling from the Earth’s mantle. The current number of hot spots is estimated to range between 45 and 70: these are mostly in intraplate settings, especially on oceanic lithosphere, and along divergent plate boundaries. - https://link.springer.com/chapter/10.1007/978-3-030-65968-4_13 https://link.springer.com/chapter/10.1007/978-3-030-65968-4_... > Regardless of the nature and origin of hot spots and whether they are fixed or mobile, the fact remains that there is a major thermal anomaly under Iceland, commonly referred to as the “Icelandic hot spot”. - https://onlinelibrary.wiley.com/doi/abs/10.1002/9781119850922.ch2 https://onlinelibrary.wiley.com/doi/abs/10.1002/978111985092... > The Cape Verde Islands are considered as the surface expression of a mantle plume at 500–800 km west of the African continental margin. The spatial and chronological evolution of volcanic activity, from East to West, is consistent with the slow progression of the African plate over the hotspot since at least the Oligocene - https://www.nature.com/articles/s41598-021-96897-1 https://www.nature.com/articles/s41598-021-96897-1 > Mantle plumes were discovered almost 50 years ago by Morgan and Wilson. They are long-lived (up to ~100 Ma) jets of hot matter rising from the bottom of the mantle and burning through moving lithospheric plates and continents in hot spots, forming large magmatic provinces. - https://link.springer.com/article/10.1134/S1028334X21090191 https://link.springer.com/article/10.1134/S1028334X21090191 To be clear, this only shows that some geologists use the term. It may be a small and decreasing minority found only because that's the specific search term I was looking for.

njarboe 5y ago

The hot spot versus plate movement/stress debate has been going on for many decades. Some hot spots are likely mostly caused by tectonic stress differences, but others seem likely to be from plumes. Scientists get published for novelty more than correctness, so if a theory is around for awhile and another can explain something in a different way, it is more likely to be published. Isotopic chemical data does suggest some volcanic sources come from the mantle (deep in the earth) where others are more likely crustal melting, which can be caused by tectonic decompression. I would be interested if you have a source of a review paper on the current ideas on hot spots, if you have it.