• Content count

  • Joined

  • Last visited

Community Reputation

9 Neutral

About Paranoid

  • Birthday 09/07/92

Profile Information

  • Gender
  • Location
    Warwick and Hull
  • Interests
    Weather watching, Disaster research, films, a little writing and games.
  1. The weather on the webcam looks as terrible there as it is here, you can see stuff being blown around (if you can see past all the dust and water that's stuck to the lens). Odd as the forecast on the IMO showed light winds, maybe it's a bit windier near the coast.
  2. I'm not sure about the VEI 7 classification, Pinatubo was on the low end of VEI 6 and i only know of one eruption from from Laacher See. Doesn't look like there's much information on it out on the interweb.
  3. Not sure if the volume high enough, i think Katla can manage floods with discharges of around 400,000 cubic metres a second which is pretty massive, but not enough to have an effect on ocean circulations (at least i can't remember there being any climatic disruption during the 1750s). Floods need to have discharges on the order of millions of cubic metres per second to affect the circulation in any big way i think.
  4. I think it may be quite remote, apparently little was known about it until it erupted in 1971. Last erupted 20 years ago with a VEI 5 eruption.
  5. I think it's the site of a landslide several thousand years ago. I can't be certain but there are other features on the Canary Islands that look like that too and the chain in general has a history of landslides. If it was a caldera there should be some evidence of the rim above sea level on the other side of the area you labelled.
  6. Noticed on Jon Frimann's blog that as well as the earthquake swarm at Katla yesterday there was also one at Askja in Northeast Iceland. Askja is also capable of large explosive eruptions.
  7. Re the possibility of flank collapse: From what i've read in places, the previous landslide that occured on El Hierro, whilst huge in terms of the total volume of material that fell into the sea, it didn't occur all at once, rather with a number of landslides over a period of hours or day. Local tsunamis are still possible under that scenario though. This is the paper i was reading, hopefully i've interpreted it correctly:
  8. Yeah, i've been having a look at the island and it doesn't look like a shield volcano, and the cinder cones suggest it's not exactly a stratovolcano so i don't think a large explosive eruption will be as likely to occur. Anything within the range of VEI 1-3 is possible i'd say, as it's unlikely to be entirely effusive or explosive. A small to moderate eruption column accompanied by some lava flows is my best bet. @ SB: Quaternary merely refers to the period in which it was erupted (within the last 2.5 million years roughly) and trachybasaltic rock is a combination of trachyite and basalt, which are both from fairly non-viscous lavas, like those at Hawaii but probably not quite as runny. Tuff is a rock formed by accumulated volcanic ash (evidence of some explosive activity).
  9. It probably all depends really on the internal pressures and dissolved gases within the magma, but basaltic lavas are certainly capable of producing VEI 3-4 eruptions. I can't claim to be an expert though, and also as far as i know there is only one historical eruption at El Hierro so i'm not sure what to expect exactly (epic vulcanology cliche). Found this on the basalt page on wikipedia: "Basalt which erupts under open air (that is, subaerially) forms three distinct types of lava or volcanic deposits: scoria; ash or cinder (breccia); and lava flows. Basalt in the tops of subaerial lava flows and cinder cones will often be highly vesiculated, imparting a lightweight "frothy" texture to the rock. Basaltic cinders are often red, coloured by oxidized iron from weathered iron-rich minerals such as pyroxene. `A`a types of blocky, cinder and breccia flows of thick, viscous basaltic lava are common in Hawaii. Pahoehoe is a highly fluid, hot form of basalt which tends to form thin aprons of molten lava which fill up hollows and sometimes forms lava lakes. Lava tubes are common features of pahoehoe eruptions. Basaltic tuff or pyroclastic rocks are rare but not unknown. Usually basalt is too hot and fluid to build up sufficient pressure to form explosive lava eruptions but occasionally this will happen by trapping of the lava within the volcanic throat and build up of volcanic gases. Hawaii's Mauna Loa volcano erupted in this way in the 19th century, as did Mount Tarawera, New Zealand in its violent 1886 eruption. Maar volcanoes are typical of small basalt tuffs, formed by explosive eruption of basalt through the crust, forming an apron of mixed basalt and wall rock breccia and a fan of basalt tuff further out from the volcano."
  10. Ah, basaltic lavas usually come from less explosive eruptions, although if any water intrusions happen that can cause some quite powerful eruptions like we saw with Eyjafjallakjokull last year and possibly with Grimsvotn earlier this year.
  11. Hot spot refers to the plume of magma that feeds it (usually they are responsible for volcanoes that are well away from plate boundaries, like Hawaii.) and not the activity of the volcano. Yellowstone is a hotspot volcano and that erupts every 640,000 years, which also goes to show that hot spot volcanoes do not always have effusive eruptions, although it does seem to be more common than explosive ones. If anyone knows that type of lava that has previously been erupted at El Hierro then you can get an idea of what sort of eruption will occur.
  12. I think a massive explosion (a'la Krakatoa) would only happen if water was injected directly into the magma chamber so the pressure couldn't be easily released into the surrounding water.
  13. Some of the tremors might be due to wind, there was a gale warning for the south of Iceland last i saw.
  14. From when i had a look on the IMO's website earlier, a few of the quakes were above Mag 2 with a fair number above Mag 1.
  15. Ah, in that case it might be the Hekla geophone picking up activity from Katla (one of the theories i've read on Jon Frimann's blog).