[HN Gopher] 900-mile mantle pipeline connects Galapagos to Panama
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900-mile mantle pipeline connects Galapagos to Panama
Author : PaulHoule
Score : 41 points
Date : 2021-11-22 17:10 UTC (5 hours ago)
(HTM) web link (news.cornell.edu)
(TXT) w3m dump (news.cornell.edu)
| poorjohnmacafee wrote:
| 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 wrote:
| Off-topic, but can you recommend some geology podcasts, either
| science-centric or for the layperson?
| mikelockz wrote:
| I liked Dick Gibson's History of Earth podcast
| https://historyoftheearthcalendar.blogspot.com/
|
| And Dr. Christian Shorey Earth and Environmental Systems
| podcast https://geology.mines.edu/sygn101-podcasts/
| mutagen wrote:
| An acquaintance of mine is a big fan of Nick Zenter's videos
| on Youtube.
|
| https://www.youtube.com/user/GeologyNick
| rich_sasha wrote:
| 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 wrote:
| 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
| _...
|
| > 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/10.1002/978111985092...
|
| > 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
|
| > 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
|
| 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.
| pmdulaney wrote:
| I understand the article to be saying that there is a water
| spring in Panama that is fed by a source in the Galapagos
| Islands. Is that correct?
| mikestew wrote:
| The way I read it is, the water spring is fed from whatever
| lies under Panama. However, there are a lot of helium isotopes
| in the water from that spring. It is theorized that the helium
| isotopes come from the magna flow from the Galapagos, which
| gets into the water. IOW, the _water_ is from Panama, but the
| _magma_ (as thus, the helium isotopes) come from the Galapagos.
| Regardless, the interesting part is that no matter where that
| water comes from, magma can apparently spread out laterally
| rather than just making islands and volcanoes.
|
| But that's just my reading, I'm probably just as confused.
| gus_massa wrote:
| No.
|
| [Remainder to understand my explanation: When "lava" is under
| earth, it's called "magma". I had to look at Wikipedia because
| I never remember. https://xkcd.com/903/ ]
|
| There is a big mantle plume under the Galapagos islands
| https://en.wikipedia.org/wiki/Mantle_plume . Imagine a lot of
| magma, and some part of it escapes and goes to the volcanoes
| and you see it as lava.
|
| They discovered that there is a "river" of magma that goes from
| the plume of magma under the Galapagos to Panama.
|
| In Panama the magma meets some underneath water, an some of the
| gas disolved in the magma goes to the water. Then the water
| colds down, and after some time it appears in a few springs in
| Panama.
|
| They realize this, because they analyzed the gases disolved in
| the water of the springs.
|
| There is no water traveling from the Galapagos to Panama.
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(page generated 2021-11-22 23:01 UTC)