The VC Bar

Welcome to the Volcano Café bar, a place for all things on or off topic and inane ramblings. There has been a need of late to find a place better suited to various theories, long comments and enthusiasm. This page will be less moderated than the main article pages and cleared out every month (this may change depending on use).

Have fun and don’t forget to tip the barman 😉

1,933 thoughts on “The VC Bar

  1. Need to pick some brains:

    I’m sorta working on deep background for a SciFi story, set on an earth-like planet currently deep in ice-age. Far less oceans & seas than our ~70%, think ‘Great Lakes’ / Caspian-type hydrology, so ice-caps’ spread stalled for lack of water. Instead, permafrost & tundra down to ~35º N/S, boreal to ~ 20º N/S, give or take. Then mostly-arid ‘High Plains’ to low latitudes…

    The would-be settlers were promised a global inter-glacial, are NOT amused…

    That aside, do we *need* oceans to make plate tectonics as we know it work ?

    There’s the fluids cycle, from trench to volcanism, of course, of course.
    IIRC, the only *rapidly* spreading dry-foot ridges are in Iceland and E-Africa, the latter around Afar.
    Likewise, there seems no land-based equivalent of subduction trenches. IIRC, Death Valley, Dead Sea etc are ‘pull apart’ features as passing plates side-swipe. Similar densities mean colliding ‘continental’ plates tend to pile up until they erode or de-laminate…

    My preliminary take would be scattered intra-plate-type plume volcanism, akin to Tibesti Massif. Tall enough for snow-cap, so permanent springs & streams…

    The would-be settlers are now eyeing a large, mostly-dormant, breached caldera. There are some hot springs, with potentially useful geo-thermal mineralogy. The crater-lake’s spill-valley’s sun-facing slope is distinctly milder than most of the surrounds. There are convenient non-volcanic springs. Mid-level terraces are safely above bottom lands’ floods and fogs, yet some-what sheltered from prevailing wind…

    Thoughts ??

    • Katabatic wind might be a significant hazard. Antarctica might be a good reference for your geologic reference. There are many volcanoes under it’s ice that have only recently been discovered. I think the last press release was something like 91 previously unknown ones.

      Don’t forget that Tuyas form from icebound volcanoes.

    • Effectively, it is a Venus with a better climate. Or Mars, also with a better climate. You may get plate tectonics: whether water is needed for that is far from certain. If so, you will have mid-ocean ridges but far above any water, with deep-lying oceanic plates around them. Quite infertile. You will also have higher-lying areas build by silicic volcanism and plumes, similar to our continents, perhaps 4 km above the ocean floors (a bit less than on earth because of the lack of oceans) Subduction volcanism would be hindered by a lack of water. On the other hand any water there is will collect in the subduction trenches so the subducting plate will carry some water. Plume volcanism will occur as on earth. They will push up big bulges (as in Yellowstone) but it will be very cold on top – not ideal for living on. A rift valley might be perfect. Something like the east-african rift: kilometers deep compared to the bulge (warmer and a denser atmosphere), rivers coming down the slope from the glaciers on top, and some thermal heat.

      Do look at the atmosphere. If the scale height is like earth but the oceans are mostly dry, you may end up with rather thin air on the continents, similar to that on top of Mauna Kea. (Think the harandra of Malacandra.) This is another reason to prefer a rift valley.

      • Mars is too small for tectonics
        It have lost too much internal heat

        The litosphere on mars is very thick

        But mars is still warm inside, and may erupt once ever 50 million years.
        Some flows on Mars are very young looking

        • You say Mars is too cold and Mars is still warm inside… Mars has a stagnant lid but so does Venus. The lid actually insulates very well and this keep Mars from cooling too fast. Whether the mantle of Mars is convective is something we will find out once there are more seismographs.

      • Mars is warm inside
        But not as warm
        as Earth is inside.

        But have cooled too much, for frequent volcanism and tectonics.

        Mars is a smaller body and have cooled more and its not tidaly heated.

        Mars cooling rate is between Earth and our Moon

  2. Weird double drop of pressure at the summit of Kilauea, it is the first time I see this happening, DI events deflate the summit once, not twice, and the second drop is also strangely rapid. It is also preceded just about 15 minutes before or so by a drumbeat swarm with about 120 LP events (shallow depth), I doubt that is coincidence.

    There were also 2 deep tremors yesterday (presumably from Pahala) at 19:26 and 22:15 UTC.

      • Since a month or so, the flat minima during a DI event have been ‘humped’ with a small increase followed by a decrease midway through the minimum. Today’s weird sudden collapse happened at about the point where it would have had this increase. Did something collapse? Let’s see how the recovery goes. The DI events now seem to communicate with the magma near Pu’u’O’o which shows pressure increase when the DI curve at Kilauea are steepest (both during the decline and recovery). My guess is that the cause for today’s collapse is somewhere on the rift zone.

        Did the cameras show anything?

    • It has now recovered from the DI event, but stabilized down from the previous peaks, by about the amount of collapse.

    • Ever since this event Di events have been behaving weird, they seem to overlap each other.

  3. Grimsvötn is very Intresting now
    The ice in the South Caldera is melting
    And have acually melted alot since 1998. Since 2011 melting in the wall have increased alot.

    Geothermal activity have increased enormously after 2017.
    Now There is a warm open pool at the calderas rim, thats warm to scalding hot in places. Its heating up

    This is shallow magma thats constantly accumulating and exciting the geothermal systems.
    The uppermost magma chamber is told to be around 50 km3 in volume
    And be feed by an open conduit – dyke from below.

    • A key piece of evidence in Sigmarsson’s talk was the concentration of the element thorium in samples of ash and pumice from each Grímsvötn eruption of the 20th century. These show an increase in Th concentration over time. This suggests that they all came from the same source beneath the volcano (the magma chamber), where growth of crystals of low-Th minerals results in an increase in concentration in the remaining melt. This melt was erupted in each of the events that produced the samples e.g. in 1998 or 2004, and was probably left over from the huge Laki eruption in 1783. The Grímsvötn 2011 samples contain much less Th than previous eruptions. This implies that it is a different magma: hotter, richer in gas, and closer to the composition of the original melt that formed in the mantle.

      • Jesper, when you give text from someone else, can you please specify where you took it from? I believe this was copied from all-geo.org

        • I forgot …
          Its me thats dementia 😉

          Yes forgot to
          Copy that adress and notice

  4. Given much of the porous caldera wall material will be threaded and bound by permafrost, will a skewed thaw affect stability ??

    Yes, Mt. St.Helens, I’m thinking of YOU !!

  5. How gas rich is Grimsvötns basaltic magma?

    I knows that Kilaūea was extremely gas rich, and extremely fluid too so allows
    all gases to escape the magma at the summit as vog. 15 000 tones everyday
    Gassing the entire Island chain.

    Holuhraun was extremely gas rich and very fluid as well 60 000 tons everyday for months. Very gas rich basalt

    Carl says Grimsvötn haves a very very sulfur rich magma, perhaps the most So2 rich of all basaltic magmas
    Whats the sulfur gas content of Grimsvötn?
    Its the ice and water that makes it explosive

    • Leilani had 60 000 tons a day of sulfur.

      Halema’uma’u was 8000 to
      10 000 tons For a decade

    • Saw it last night. It is just becoming visible in the evening. Don’t expect too much. The sky is pretty bright (for us in the far north) and the comet is a decent one but not spectacular. But it has been 15 years since the last bright one and this will have to do! The tail was very obvious. Now comets are supposed to predict bad news. A VEI-6, perhaps? Certainly this comet is not bright enough for a VEI-7? (Which you wouldn’t want anyway. Imagine what the world-wide sulphate would do to solar power, and a lack of solar heating would probably also suppress wind.)

      • Dunno, I’m just wondering what this thunderstorm that rolled through this evening did to the photovoltaic array over at Saufley Field. The main core of the storm rolled right across it and showed a copious amount of lightning there.

        My peppers loved the torrential rain. I’ve got 2 Carolina Reaper pods and a Ghost pepper coming in right now 😀 (And several blooms on all four plants.)

        Side note. Mu grandson has already made a request for 2 of my Reapers when they fill out and ripen. Seems he wants to see if his future father-in-law has the temerity to try them. His future brother-in-law has already learned to not boast to him. He wound up with a dried ghost pepper but seems to have not been up to the task.

  6. Im so supprised to find recent volcanism in South East Spain,a few cinder cones
    That nust be holocene in age.
    Volcanoes in mainland Spain?
    Found them in Google Earth.
    Only 80 kilometers north east of Barcelona City. What causes volcanism there?

    • Africa !!

      Like the Eifel region, caused by Africa’s rotating collision with Europe, and probable subduction of oceanic crust / islands that got in the way.

      There’s on-going eruptions in Western Med, including an island / sea-mount that, whenever it Surtseys, is claimed by several countries, nearly prompting several nasty little wars…

      Um, much argument over possibility that the Gibraltar Arc may evolve to a full-on subduction zone, like the Carib and South Scotia. If so, it would mark the beginning of the beginning of the end for Atlantic, and starts another turn of the Wilson Cycle…

      Would such subduction’s back-arc volcanism close the Med at Gibraltar to land-bridge Africa to Europe, as similar volcanism did for N/S America at eg Panama ?

      • The Med volcanism is caused by different faults running east-west. The Catalan volcanism is more closely related to western europe and is oriented NNW-SSE

    • It is part of the main volcanic zone across western europe, which runs from the Eiffel via the Massif Central to southern Spain. It follows a series of grabens, from the Rhine graben to Spain, some of which are causes by the Alps (pushing France to the west) and some maybe caused by Spain rotating into Europe.

  7. My sister thinks the world ending by a volcanic eruption is lame and anticlimactic. Even when I brought up the sun changing color and the amazing cooling. still lame
    The widespread ashfall and/or gas clouds? Lame
    Horrific famine and epidemics? Still anticlimactic.
    She won’t be saying when it happens.

    • I’m just saying, volcanic eruption just doesn’t do it for me. Is it terrible? Very. But knowing there are BETTER ways for the world to end spoils it for me. Also! The world, ending for a year? That takes too looooong, the world needs to end faster.

      • Comet Swift Tuttle
        30 km wide and 60 kilometers a second
        Is then your dream

        One of the largest threats to humidity
        Smallest change from Jupiter can bring the monster on collision course.

        Way larger than KT impactor

        Your ultimate goal?
        Mr world destroyer 🙂

      • For now Swift Tuttle cannot hit us at all
        We are competely safe: But after year 4000 orbital forecasts gets more blurry due to Jupiters gravity influense.

        But still a relatively safe comet, concern wise

        With a relative velocity of 60 km/s,
        an Earth impact would have an estimated energy of ~27 times that of the Cretaceous–Paleogene impactor. The comet has been described as “the single most dangerous object known to humanity”

        An impact woud fill Earths atmosphere with vaporized materials much hotter than the surface of the sun, everything woud start burning

      • Some say the world will end in fire,
        Some say in ice.
        From what I’ve tasted of desire
        I hold with those who favor fire.
        But if it had to perish twice,
        I think I know enough of hate
        To say that for destruction ice
        Is also great
        And would suffice.

        (Robert Frost)

  8. Hi Albert I dont want to flood VC with my annoying commentary

    But is volcanism possible at Thornqvist Zone? Its possible to do some geothermal energy there in Skåne
    The edge beetween Baltic Craton and the more movable European litosphere

    During the jurassic there was some little divergence at Thornqvist Zone at that allowed monogentic basaltic volcanism to take place in Sweden.
    Is there possibility for this again?

    • Not at the moment. These old zones can reactivate under the right conditions. But that seems unlikely until the next supercontinent has formed and is breaking up again – and probably not even then. A hot spot may of course accidentally come underneath. I think not even Tallis will want to wait for that.

  9. Since Carl is ( probaly working )
    on the next Grimsvötn post

    Albert can you find the Latest satelite image of Grimsvötns caldera?
    I wants to see how geothermal melting is going

    • If you mean the “province of China” bit then the issue is ISO 3166 which officially designates the name of Taiwan as “Taiwan (Province of China)”. I know when this designation has appeared previously that authors of these papers have said they were forced to use the ISO designation (as they have to for every country) due to policy of their institutions and/or funding bodies.

      I believe some US and Canadian universities have created an exemption from using the ISO designation for Taiwan though.

      • ISO 3166 defines the country codes. It does not stipulate the name of the country or region – that is not defined by committee. And this paper is inconsistent in this anyway, ie it uses ‘USA’ which is not on the ISO list! The editors should leave politics out of the science.

        • https://www.taiwannews.com.tw/en/news/3812381

          TAIPEI (Taiwan News) — Taiwan’s Control Yuan on Thursday (Nov. 7) urged the Executive Yuan to address the erroneous labeling of Taiwan as a province of China by the International Organization for Standardization (ISO).

          The island has been wrongly referred to as “Taiwan, Province of China” since 1974 in ISO 3166, a standard that designates codes to represent the names of countries and their subdivisions, said Peter Chang (張武修) of the Control Yuan, an investigative agency that monitors other government branches.

          The standard-setting body has also obstructed Taiwan from participating in events related to ISO matters

        • Here’s a very recent news iitem.

          UBC quietly changes references to Taiwan amid sensitive political climate
          July 4, 2020</i?

          In past reports, the university simply listed the island as “Taiwan,” but in the recent 2019/20 enrolment report, it was lengthier: “Taiwan (Province of China).”

          In a written statement from Kurt Heinrich, UBC Media Relations senior communications director, he said this is because in 2018, UBC’s data governance steering committee adopted International Organization for Standardization (ISO) data standards.

          The ISO, which is recognized by the United Nations, has referred to Taiwan as “Province of China” since 1974 under ISO 3166, and the UN switched its recognition of China from the Republic of China (Taiwan) to the People’s Republic of China (Mainland China) in 1971.

          In a later email, the university stated that the adoption of ISO standards was “necessary for the university’s successful transition to Workday

          …“To put ‘Province of China’ after the name is to politicize the name,” said Dr. Timothy Brook, a UBC professor and an expert in Chinese history.

          I do not know if the authors of the Lancet paper had a choice in the matter is all I am saying.

          • But they have now backed down

            https://www.citynews1130.com/2020/07/07/taiwanese-authorities-accept-ubc-apology/

            VANCOUVER (NEWS 1130) – The University of British Columbia has back-tracked on a controversial designation of Taiwan which had been threatening to create a new political challenge for the school.

            The Taipei Economic and Cultural Office in Vancouver has issued a statement, saying it accepts UBC’s decision to move away from referencing Taiwan as a “province of China.”

            “We welcome that UBC would work in line with the spirit of academic neutrality, and refer us as Taiwan in the future,” said Charles Teng, Director of the office.

          • I am sure the authors had no choice other than not publish. But I would not have accepted political statements (in any direction) to be put into my papers.

          • Lancet editor Richard Horton once wrote an editorial calling for Taiwan to be re-admitted to the WHO and always just uses Taiwan in Lancet articles published under his own name, so it definitely isn’t them.

            I do wonder about…

            Funding
            Bill & Melinda Gates Foundation.

            Although Bill Gates has personally praised Taiwan’s covid-19 response he is also staying close to China

            https://news.cgtn.com/news/2020-02-22/Xi-Jinping-replies-to-letter-from-Bill-Gates-on-fight-against-COVID-19-OhuJHlc5yw/index.html

            Xi Jinping replies to letter from Bill Gates on fight against COVID-19

            In his letter dated February 20, the Chinese president wrote: “I deeply appreciate the act of generosity of the Bill & Melinda Gates Foundation and your letter of solidarity to the Chinese people at such an important moment.”

            Gates said in his letter on February 6 that his foundation has committed up to 100 million U.S. dollars in emergency funding, much of which will help China bolster epidemiological research, emergency intervention, and the research and development of drugs, vaccines, and diagnostics.

            …I support your cooperation with relevant Chinese institutions, and look forward to enhanced coordination and concerted efforts in the international community for the sake of health and well-being of all,” Xi added.

    • Despite the attraction of large populations and low regulations for corporate competitiveness and profit potential, I doubt the world will get to 2064 without a nuclear war and/or serious natural or engineered pandemic. Human consumption remains an unsustainable demand on the biosphere and it will result in natural disasters and resource conflicts; while offshoring industry to low wage, low regulation countries results in domestic unemployment.

      The logical military response of all nations, unfortunately, is to perceive competing populations as enemies; rich nations for their excessive consumption and poor nations as industry, technology and employment thieves. It won’t get any better; thus the world is primed for conflict and other disasters to reduce the population to a sustainable level, probably below 2 billion.

      The end of the current model of civilization will probably come about as a result of High Altitude Electromagnetic Pulse about 400 km above each continent to cripple the electricity grids, fuel, water, sanitation and food supplies to most urban populations; resulting in starvation and disease and intense competition for survival.

  10. All
    Volcano watch at the HVO has an article “Deep repeating earthquakes beneath Mauna Kea”. Just published this May and they are tracked back to 1999.

    “The small, repeating earthquakes occur at depths of about 20–25 km (12–15 mi) directly beneath Mauna Kea’s summit and happen every 7–12 minutes with surprising regularity. Furthermore, the repeating events can be detected going back to at least 1999.”

    https://volcanoes.usgs.gov/observatories/hvo/hvo_volcano_watch.html

    Mac

  11. Interesting…

    I get the impression there is fresh stuff rising from a deeper source to base of a large, mid-way magma chamber, rattling the pasty contents serving as its conduit’s lid…

    How much shallower before HVO begins muttering about possible evolution to ‘harmonic tremor’ and closing access roads ??

  12. Question for the VC Bar
    Is it possible for a deep sea hydrothermal black smoker to be hot enough to glow?
    400 C and it is not enough for it to glow

    But can they emerge at 700 C ?
    Then the supercritical geothermal fluid woud glow ghostly cherry red in darkness

    • IMHO, there’s enough hydrothermal circulation to quench it underground. If hot enough to glow, would be a Surtseyan lava vent rather than a ‘Black Smoker’…

      Yes, there’s daring footage of ‘blubbing’ pillow lava but, IIRC, that was shallow. I’ve read reports of deeper vents producing pillow lava, so a ‘Right Place, Right Time’ ROV might catch glow…

      Oh, and a deep-sea vent that produces a pumice raft must surely have delivered glowing-hot lava…

    • Not black smokers. Those are effectively deep water fumaroles. Lava though will come out at any range of temperatures. Komatitiite was erupted under water. But because of the sea water, the surface immediately cools and form a solid layer (that is why you get pillow lava). You would need to look right into the vent. Of course, use an infrared camera and it will stand out like a sore thumb. Recommended anyway – you would not want to swim into an invisible black smoker.

  13. A hurricane is heading for Hawai’i. It is predicted to be in decline on arrival, but a decline from a major hurricane can still be dangerous. Perhaps the rain will add to the Kilauea lake.

  14. Hi Albert! You makes amazing posts articles

    Next post should be about Auckland Volcanic Field! its history, its eruptions, its geology: and What happens If an eruption happens in the middle of the megacity today! 🙂
    Its s risk politicians and autorities there always haves in the backmind.
    But the chance of eruption in my lifetime is very small.

    The mammoth city of Auckland in NZ does sit on a monogentic field, created by a weak local hotspot.
    Very sillica poor alkaline basalts
    Mostly scoria cones.
    A New cinder cone in the city is always a possibilty: and what woud happen?
    The next article

    • Yea! that woud make a very good VC post indeed.
      The last eruption that built Rangitoto Island just a few km outside Auckland was a pretty large eruption. It lasted 5 to 10 years according to GEO – NET.
      I expect most eruptions in the city arera to just last a few weeks or months, or just days.
      I visited Auckland 2010 and never realised it was volcanic

    • Even a small Auckland cinder cone in the city woud be world news. Apparently Rangitotos 2,3 km3 erupted more materials than the rest of the entire monogentic field entire 300 000 years eruptions history.

      So Auckland volcanic field is Not a very active or productive arera. Very small eruptions on avarge. The field likley never reaches 0,1 km3 per eruption.
      Minior magma production, must be a very weak hotspot

    • Albert / or anyone here
      If Auckland erupts again, is it possible to divert the lava flows from major streets?
      Lava is a very good insulator, so cooling with water, only cools the outer surface, while the hot insulated pasty interior pushes foreward. Making them hard to cool through with water. Insulated pahoehoe flows been found as 20 kilometer long submarine flows
      Rock is a good insulator.

      In Hawaii they had huge problems with cooling pahoehoe flows, water cools only the outer surface crust.

      Auckland volcanic field will almost certainly produce rough Aa lava because higher eruptive rates and a bit higher viscosity. In Heimeay they apparently cooled a massive advancing Aa flow front.
      But Im not soure If the Heimeay lava tryed to directly advance Into the city.
      Most of the 1973 lavas already flowed east of the town when it started. But seems like the Icelanders managed to cool that breakout.

      But stopping a massive flow with water is not easy

      • If you want to stop lava, you need to give it somewhere else to go. There has been some success with levees but only as a diversion, not as a full stop.

      • I knows that Auckland volcanic field is a very weak melting source.
        But If an eruption happens in the Big city, is it possible to see that a few years before it happens?

  15. Hurricane Douglas

    …DOUGLAS MOVING QUICKLY WEST-NORTHWESTWARD AS A CATEGORY-3
    HURRICANE…

    SUMMARY OF 500 AM HST…1500 UTC…INFORMATION
    ———————————————-
    LOCATION…13.6N 135.9W
    ABOUT 1335 MI…2150 KM ESE OF HILO HAWAII
    MAXIMUM SUSTAINED WINDS…120 MPH…195 KM/H
    PRESENT MOVEMENT…WNW OR 290 DEGREES AT 20 MPH…31 KM/H
    MINIMUM CENTRAL PRESSURE…964 MB…28.47 INCHES

  16. Meanwhile off Texas Tropical Depression 8

    Elon Musk tweeted recently that they would attempt a 150 metre hop from the launch pad with Starship prototype SN5 this week but even though the storm is forecast well north and not too strong that could still change somewhat so you would think they would err on the precautionary side – but it is SpaceX !!

    Some models and ensemble members suggest it could get to Cat 1 as Hurricane Hanna by landfall. Let’s hope not.

    • Now forecast to be Hurricane Hanna

      A Hurricane Warning has been issued from Baffin Bay northward to
      Mesquite Bay, Texas.

      A Storm Surge Warning has been issued from Baffin Bay to Sargent,
      Texas, including Corpus Christi Bay, Copano Bay, Aransas Bay, San
      Antonio Bay and Matagorda Bay.

      SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

      A Storm Surge Warning is in effect for…
      * Baffin Bay to Sargent Texas

      A Hurricane Warning is in effect for…
      * Baffin Bay to Mesquite Bay Texas

      A Tropical Storm Warning is in effect for…
      * Mouth of the Rio Grande to Baffin Bay Texas
      * Mesquite Bay to San Luis Pass Texas

      • BULLETIN
        Tropical Storm Hanna Intermediate Advisory Number 10A…Corrected
        NWS National Hurricane Center Miami FL AL082020
        700 AM CDT Sat Jul 25 2020

        Corrected to add hurricane-force wind radii and hourly updates

        …NOAA HURRICANE HUNTERS AND DOPPLER WEATHER RADARS FIND HANNA HAS BECOME THE FIRST HURRICANE OF THE 2020 ATLANTIC HURRICANE SEASON…

        SUMMARY OF 700 AM CDT…1200 UTC…INFORMATION
        ———————————————-
        LOCATION…27.1N 96.0W
        ABOUT 90 MI…150 KM ENE OF PORT MANSFIELD TEXAS
        ABOUT 100 MI…160 KM ESE OF CORPUS CHRISTI TEXAS
        MAXIMUM SUSTAINED WINDS…75 MPH…120 KM/H
        PRESENT MOVEMENT…W OR 270 DEGREES AT 9 MPH…15 KM/H
        MINIMUM CENTRAL PRESSURE…982 MB…29.00 INCHES

    • Just hot gases according to GeoNet

      A volcano can have glowing fumaroles with magma being deep underground.
      But this is a clear sign that white Island is drying out its interior

  17. Im amazed that Nyiragongo even haves a lava lake! It basicaly erupts
    Kauai late stage dying postshield lavas.
    Nyiragongo is hardly any partial melting at all. Why does it open conduit with hardly any magma production at all? Superalkaline super – undersaturated in sillica. Hardly any melting at all.
    I think less than 1% mantle melting form Nyiragongo magma seriers.
    Nyiragongo magmas are not common.

    Nephelinite the Nyiragongo magma hardly exist on Earth, its not something thats very common. Nephelinite volcanoes tends to be monogenetic too.
    Nephelinite is the igenous rock thats most rare on Earths surface, knowing its produced in the most minimal ammounts in the mantle.
    The rarest igenous rock

    • Yes thats true… Nephelinite is not something thats very common…
      Its only found in a few outcrops in germanys Eifel Volcanic field in entire Euro – Asia.
      Nyiragongo is the worlds ONLY active Nephelinite volcano.

      Nephelinite makes up only a tiny tiny tiny tiny fraction of the worlds igenous rocks.
      Every rock collectors dream

  18. As a complete aside, last night I was idly playing the PC game “Shadow of the Tomb Raider”, when Lara Croft came face to face with a catastrophic lahar from a nearby eruption. And it was surprisingly well depicted, too!

    Naturally she outrode it with her ridiculous athletic and inexhaustible springiness. But as a Volcano Cafe reader I was for a few moments taken by the lahar experience in the game.
    Seems that some game writers do pay attention!

    • Happily, there’s lots of quality video of such now, rather than nigh-incoherent reports by traumatised survivors…

      Speaking of Lahars, looks like those around Mt Rainier were even bigger and went further than previously estimated. But, the consequences of cone’s ice-cap thawing and un-locking the permafrost which has bound the old rim & flanks above the snow-line may be scary.

      May just take one really bad storm / ‘atmospheric river’. Lotsa rain above snow-line, something Alpine avalanche guards know to fear. Best case, impressive but localised avalanche(s) & mild lahars. Worst case, flank slump.

      IIRC, not enough hot rock near surface for a full-on lateral blast per Mt St Helens, which managed a LARGE flank bulge prior…

  19. Help! USGS has updated is earthquake map earthquake.usgs.gov/earthquakes/map
    It seems the most useful functionality is gone. It was possible to instantly zoom to several areas of usual interest. Now you get the continental US or the entire world as the only options. In the past you could instantly get to Hawai’i, Alaska and several other areas. Has anyone found a way around this? Other than back to manual?

    • Nope, couldn’t find it either. I guess these functions were not used by most users and got the axe due to low usage.

      If everyone here contacts them, maybe they’ll put them back?

    • Albert
      If you click on the box “Only list earthquakes shown on map”, It will list those quakes so when you zoom onto the big island, it will only list those.

      Let me know if this is what you were looking for.
      Mac

      • But you need to manually zoom to the area. Before, that took one click. Now it is much more work.

    • You have to hit “refresh” then put the terrain layer and then it shows the earthquakes. The zoom feature still works but only from “world” to US. It is not an improvement.

    • Were there any ‘great quakes’ in the days after the Carrington Event or the Quebec Outage ??

      Hmm. Rather than blame solar protons and piezo-electricity, might do better to suggest that the solar blast’s squidging of Earth’s magnetic field has caused ‘shoo-fly’ twitch of mantle…

  20. Texas cave sediment upends meteorite explanation for global cooling

    https://phys.org/news/2020-07-texas-cave-sediment-upends-meteorite.html
    https://advances.sciencemag.org/content/6/31/eaax8587
    ( Latter, referenced by physorg, is NOT paywalled !!)
    fair-use quote:
    “This work shows that the geochemical signature associated with the cooling event is not unique but occurred four times between 9,000 and 15,000 years ago,” said Alan Brandon, Ph.D., professor of geosciences at University of Houston. “Thus, the trigger for this cooling event didn’t come from space. Prior geochemical evidence for a large meteor exploding in the atmosphere instead reflects a period of major volcanic eruptions.”
    /

    Perhaps the eruptions were triggered by isostatic off-loading following retreat of ice-caps ?

    FWIW, though *not* covered by this research, does seem there was a major tektite fall during that period, but a drama rather than a crisis…

    • An ice-age glacier collects a lot of meteorite over time. When it melts you will get such a signature wherever the melt water drops it. I am on record as being sceptical about the impact hypothesis. Too much evidence is lacking: it does not quite hang together to me.

      • IIRC, the tektite strewn field does not match glacial moraine patterns, where you’d expect such ‘erratics’ to appear. Still, several major volcanic eruptions, perhaps associated with ice-cap off-loading / isostasis, seem a more likely culprit. Didn’t some Icelandic volcanoes become uppity thus ?
        “Decreasing lithostatic pressure as the glacier melts and vigorous crustal movements caused by rapid isostatic rebound may trigger intense volcanism until a new pressure equilibrium has been established.”
        Sorry, $$ paywalled…
        https://link.springer.com/article/10.1007/BF00312320

        ( Cluedo: Miss Alaska with sooty bonfire, not Cpt Bolide with blunderbuss… )

  21. Hard to believe that the explosion in Lebanon was registered only as a 3.3 on emsc. Just shows what 2750 tonnes of Ammonium Nitrate can do and how we take a mag 3 as negligible

  22. The USGS earthquake map has had the previous zoom options restored. A welcome addition, gratefully received. It is still the new interface which seems faster than the previous one, but the globe on the left now opens up a list of options.

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