Watching volcanoes from space: Part 2

This GOES-13 image captures the ash plume from Puyehe Cordón-Calle on 6 June 2011. Note how the plume changes direction as it meets a weather system. (NOAA)

This GOES-13 image captures the ash plume from Puyehe Cordón-Calle on 6 June 2011. Note how the plume changes direction as it meets a weather system. (NOAA)
(click on the images to see a larger version)

What follows is a very rough guide to the satellites and their systems that routinely feature in volcano-watching. For anyone interested in learning more, most of the systems have dedicated websites with a lot more information. Just Google the name of the system/satellite, or search through the NASA, NOAA or USGS main sites (way too may links to list!).

GOES: surveillance from on high

Of the geosynchronous satellites it is the National Oceanic and Atmospheric Administration’s GOES (Geostationary Operational Environmental Satellite) meteorological system that is the most often used to aid volcano monitoring. The first GOES satellite was launched in 1975, and today there are four US-operated platforms in orbit. Two are primary satellites (GOES-East and GOES-West) that provide coverage of North America, while GOES-South covers South America. A fourth satellite is held in orbital storage, and is brought online to cover any problems with the others, or to add additional data during extreme weather events. The GOES network is complemented by other weather satellites, such as the Japanese MTSAT and European METEOSAT programmes, to provide global coverage.

Due to the high altitude of the GOES satellite it has no value for close monitoring of the volcanoes themselves, but it is a useful tool for tracking ash plumes.

POES: polar weather-watchers

AVHRR imagery from the sensor's band 4 shows Klyuchevskoy erupting on 30 September 1994. (NOAA)

AVHRR imagery from the sensor’s band 4 shows Klyuchevskoy erupting on 30 September 1994. (NOAA)

Also falling under NOAA’s purview (in partnership with the European EUMETSAT), and the true successor to that ground-breaking TIROS-1 mission, is the POES (Polar-orbiting Operational Environmental Satellite) programme. Currently there are six satellites (NOAA-15, -16, -18 and -19, and the European METOP-A and -B) in the system, two of which are the primary platforms. The constellation’s main mission is to aid weather forecasting, but the sensors can also be used to monitor volcanic eruptions.

For this the Advanced Very High-Resolution Radiometer is the most useful sensor. AVHRR is a scanning radiation-detection imager operating in six channels in its current AVHRR/3 version. It is used by day and night to map clouds, snow, ice, land-water boundaries and sea surface temperature. Examining images from the various frequency bands allows volcanic ash plumes to be easily discriminated from clouds

Landsat: imaging Earth

Perhaps the best known of the Earth imaging systems is Landsat, which began life as the Earth Resources Technology Satellite, launched on 23 July 1972. It carried the MSS (multi-spectral scanner) sensor and produced 185 x 185 km images in three spectral bands. It was renamed Landsat in 1975, and its successes led to a series of eight satellites being launched (although Landsat 6 failed to reach orbit).

Currently there are two Landsat satellites in operation, numbers 7 and 8 (see below). Landsat 7 was launched on 15 April 1999 and its main sensor is the ETM+ (Enhanced Thematic Mapper Plus), offering seven channels including a thermal (heat) channel.

EO-1: too good to kill off

Some of the most eye-wateringly stunning imagery from space in recent times has been provided by the Advanced Land Imager (ALI) sensor flying on NASA’s Earth Observing-1 satellite. EO-1 was launched on 21 November 2000 as part of NASA’s New Millennium Project. It was intended as an experimental ‘proof-of-concept’ platform for several advanced sensors, including ALI and the Hyperion hyperspectral imager, and its mission was originally expected to only last a year. However, the project was so successful that EO-1’s mission has been extended and it continues to provide imagery 12 years later.

Recorded by the ALI sensor aboard the EO-1 satellite, this view shows Tolbachik on 5 April 2013. The two frames show the same scene but in different spectral bands. The left-hand shows the scene in visible light, whereas the right-hand image shows the infrared thermal image. (NASA)

Recorded by the ALI sensor aboard the EO-1 satellite, this view shows Tolbachik on 5 April 2013. The two frames show the same scene but in different spectral bands. The left-hand frame shows the scene in visible light, whereas the right-hand frame shows the infrared thermal image. (NASA)

Like most spaceborne imaging sensors ALI samples its imagery in various bands of the frequency spectrum, which can be analysed separately or combined to create a variety of image types. Whereas earlier sensors such as ETM+ work on a ‘whisk broom’ principle, producing swathe images by scanning a mirror across the satellite’s path to build up an image on a single sensor, ALI uses the ‘push-broom’ concept, in which a series of small, fixed sensors produce a single swathe image as the satellite progresses. The principal advantage is increased reliability due to a lack of moving parts.

Landsat 8: continuing the mission

Smoke and ash can be seen in this OLI image of the recent activity at Veniamonof volcano in Alaska, 25 July 2013. (USGS)

Smoke and ash can be seen in this OLI image of the recent activity at Veniaminof volcano in Alaska, 25 July 2013. (USGS)

Building on earlier Landsat experience and drawing on technology from EO-1, NASA has recently brought Landsat 8 online. Developed under the Landsat Data Continuity Mission and launched on 11 February 2013, the new satellite was renamed as Landsat 8 on 30 May, the date on which its operational management was handed over to the US Geological Service, which is the agency responsible for the Landsat mission. With the successful implementation of Landsat 8 in operation, Landsat 5 was switched off in June this year.

Landsat 8’s primary sensors are the nine-band OLI (Operational Land Imager) and the two-band TIRS (Thermal Infrared Sensor). OLI is based on the ALI flying aboard EO-1, and is delivering superb imagery. It collects imagery in nine bands, adding a deep blue coastal/aerosol band and a cirrus band to the seven bands already offered by ALI. There are two SWIR (short-wavelength infrared) bands and a single NIR (near infrared) band, as well as red, green and blue visible bands. The latter can be combined to create a visible image (just as the red, green and blue dots on a TV screen combine). Another source of a visible image is the Panchromatic band that covers the entire visible spectrum with the exceptional resolution of 15 metres.

Meanwhile, the TIRS system looks at thermal signatures (i.e. heat) in two LWIR (long-wavelength IR) bands. The system uses two bands to help overcome distortions caused by the atmosphere. Systems such as TIRS, and other thermal detectors flying on other satellites, are very useful for discovering thermal anomalies at volcanoes, which are often an indicator of volcanic activity.

Terra: flagship of EOS

Under the grand title of Earth Observing System (EOS), NASA brought together a range of spaceborne sensors into a single generic programme that aimed to leverage their different capabilities, and to promote cross-matching and data fusion across the frequency spectrum. As well as using existing satellites, a number of new satellites have been deployed under the broad aegis of EOS.

Shiveluch again, but this time imaged by the MODIS sensor on 17 September 2002. As well as the imagery, there is a red dot at the volcano indicating a thermal anomaly. (NASA)

Shiveluch imaged by the MODIS sensor on 17 September 2002. As well as the imagery, there is a red dot at the volcano indicating a thermal anomaly. (NASA)

First of the new platforms, and ‘flagship’ of the EOS constellation, is Terra, which was launched on 18 December 1999. Among its sensors are two that are well known to volcano-watchers: ASTER and MODIS. The satellite was initially known as EOS AM-1, not on account of the initial letters of its primary sensors, but because it is the ‘morning’ satellite (see below).

MODIS (Moderate-resolution Imaging Spectro-radiometer) is a multi-purpose sensor that records in 36 slices of the spectrum across a wide swathe below the satellite. Its resolution varies between 250 and 1000 metres (according to frequency band) and is used primarily for a ‘big picture’ view.

On the other hand, ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) offers much higher image resolution (down to 15 metres in the visible bands) across 15 spectral bands, including five in the LWIR range for heat imaging. It complements MODIS by offering a better ‘close look’ capability.

A vast bank of high-resolution ASTER images (dating from 2000 and in visible, NIR, SWIR and thermal bands) for virtually every volcano in the world can be accessed through this portal:

Aqua and Aura: take the A-Train

In this context the ‘A-Train’ has nothing to do with the New York subway, or even Duke Ellington, but rather it is a multi-national convoy of EOS satellites in frozen, sun-synchronous orbits that contains two of the most important platforms for observing volcanoes: Aqua and Aura.

Altogether, there are five satellites in the ‘A-train’ (with PARASOL orbiting below, and the carbon-monitoring OCO-2 to join the train in 2014), all following a similar path over the earth a few minutes apart. Their sensors cover a number of parameters and record their results from the same place and near-synchronously, allowing the direct and near-contemporaneous comparison and fusion of data across the suite of sensors. The convoy takes its name from being the ‘Afternoon train’ – the satellites pass north over the equator at around 1.30 pm in solar time, that is the time local to their position above the earth (and conversely pass south over the equator at 1.30 am local time).

The AIRS sensor aboard Aqua traced sulfur dioxide emissions from Okmok in July 2008. (NASA)

The AIRS sensor aboard Aqua traced sulfur dioxide emissions from Okmok in July 2008. (NASA)

Aqua (EOS PM-1, launched 4 May 2002) carries MODIS, and is broadly similar in its function and capabilities to Terra (although it lacks the ASTER ‘close-look’ sensor), with the exception of its timing. Aqua is the ‘afternoon’ satellite, whereas Terra takes the ‘morning’ shift. Among the sensors carried by Aqua is the AIRS (Airborne Infrared Sounder) that, among other things, can be used to track sulfur dioxide clouds.

Aura (EOS CH-1, launched 15 July 2004) has different tasks. Among its sensors is the Ozone Measuring Instrument (OMI), the principal duty of which is to map ozone in the atmosphere. However, for volcano-watching OMI is also a very useful tool for tracking volcanic emissions. Like AIRS, it can track clouds of aerosols and also sulfur dioxide, and is very valuable in monitoring ash clouds that threaten air traffic.

The OMI instrument on Aura can trace both sulfur dioxide (left) and aerosols (right) in the atmosphere. This was the tracks of both on 8 May 2010 during the Eyjafjallajökull eruption. (NASA)

The OMI instrument on Aura can trace both sulfur dioxide (left) and aerosols (right) in the atmosphere. These simultaneous traces were recorded on 8 May 2010 during the Eyjafjallajökull eruption. (NASA)

OMI and AIRS are the current incarnations of a programme that has been ongoing since the Nimbus 7 satellite launched on 24 October 1978 with the Total Ozone Mapping Spectrometer (TOMS) aboard. The TOMS ozone mission, and its valuable volcanic ash-monitoring by-product, ended in 2005.

This was the first useable sulfur dioxide trace from the OMPS sensor aboard the new Sumoi NPP satellite. Nyiragongo, 8 May 2012. (NASA)

This was the first useable sulfur dioxide trace from the OMPS sensor aboard the new Suomi NPP satellite. Nyiragongo, 8 May 2012. (NASA)

Aqua and Aura now have a new partner in the ozone-monitoring mission in the form of the Suomi NPP (National Polar-orbiting Partnership, launched 28 October 2011) satellite, which carries a system similar to OMI known as OMPS (Ozone Mapping and Profiling Suite). The satellite also carries the VIIRS (Visible Infrared Imaging Radiometer Suite) 22-band sensor, which is similar in capability to MODIS.

Suomi NPP was launched as the pathfinder for the NPOESS (National Polar-orbiting Operational Environmental Satellite System) that would replace both NOAA’s POES system and the military meteorological satellites. By the time that Suomi NPP launched in 2011 NPOESS had already been cancelled, to be restructured as the JPSS (Joint Polar Satellite System), with the first of two new satellites (JPSS-1) to be launched in early 2017. Primary mission data reception stations for JPSS will be located on Svalbard and at McMurdo Sound in Antarctica.

A good pair of eyes

Of course, there is one other highly important ‘sensor system’ watching volcanoes from space – in the form of astronauts/cosmonauts! Armed with digital cameras, humans in space have captured some of the clearest and most revealing overhead images of volcanoes. Today the principal ‘satellite’ carrying the ‘human sensor systems’ is the International Space Station. It orbits the Earth every hour and a half at an inclination of 51.6° and at an altitude of just over 400 kilometres (although that is decaying at the rate of around a kilometre every fortnight).

© UKViggen

Shiveluch again, this time photographed from the International Space Station on 10 July 2007. (NASA)

Shiveluch again, this time photographed from the International Space Station on 10 July 2007. (NASA)

127 thoughts on “Watching volcanoes from space: Part 2

  1. @Diana
    Sorry – I had to set this post on schedule (early airport run this morning, just got in) and probably should have left a note saying it was going up this morning. If I knew how to move your latest comments here I would, but if you want to repost them here so they don’t get lost that’s fine by me!

  2. Diana: my reply to you 🙂 you should come to Iceland for holidays. Then you can visit several of the volcanoes for yourself, watch northern lights (not in summer), see the lava fields of Laki, etc… The flights from the UK can be quite cheap. Iceland Express or EasyJet.

    Carl: I could not find any reply from you. Are you sure you mail me at the correct address?

    • Hello!
      I never got a mail from you. So, I sent a mail to the adress that you log in with here.
      A few weeks ago we sent a few mails back and forth, can you reply on that one?

  3. I am working on a couple of posts at the moment, not as good as ukviggen and the others, will call it quits for tonight, my eyes are sore, I might need some help, I am not sure how to go about it and even if it is good enough

  4. Regarding the ISS and its orbit.
    As UKViggen mentioned it looses about a kilometer every other week due mainly to geomagnetic drogue. It would have fallen down a long time ago if it was not for the fact that as the orbit decay down to 330 kilometers they fire up the control thrusters and nudge it up into an orbital altitude of 435 kilometers.

    The ISS is funded up untill 2020, but can be safely operated into 2028 if there is a demand. And the Russians want to use it as a platform for an even bigger spacestation named OPSEK.

    Anyhow, sooner or later ISS is going to be decommisioned. And decomissioning means allowing it to come crashing down in as a controlled manner as possible. Normaly they loose the control and the space station ends up somewhere it shouldn’t. This is though less dangerous than it sounds. It will break up on re-entry and mostly burn up as it hits the atmospehere.

    Enter the comode. As have been noticed with previous decomissionings the comode is a serious piece of stainless steel hardware. It will not be burning up, and it wont break up. There is a good reason for the comode being bulky and made out of thick steel. You do not want your comode to fail in zero gravity.
    Ontop of that the comode is situated in the most sturdy and shielded section of the space station. This due to it being used as a shelter when there is a solar storm.

    So, if anything on the ISS would hit you in the head you can bet on it being the most expensive toilet in the history of mankind.

    (There is just no way to know how my brain will meander. I just wanted to give a short explanation on why the ISS hasn’t crashed.)

    • Here’s a bit about drag and how it varies with solar activity. From the link I gave in Part 1 (

      “Atmospheric drag is stronger when the Sun is active. Just as the air in a balloon expands and rises when heated, the atmosphere rises and expands when the Sun adds extra energy to it. The thinnest layer of atmosphere rises, and the thicker atmosphere beneath it lifts to take its place. Now, the satellite is moving through this thicker layer of the atmosphere instead of the thin layer it was in when the Sun was less active. Since the satellite moves through denser air at solar maximum, it faces more resistance. When the Sun is quiet, satellites in low Earth orbit have to boost their orbits about four times per year to make up for atmospheric drag. When solar activity is at its greatest, a satellite may have to be maneuvered every 2-3 weeks.”

  5. Hello everyone!
    Ukviggen, what a wonderful couple of posts! Thank you so much.
    Irpsit, I join Diana in her comment about your Icelandic journeys. Not so sure if I would enjoy actually being there under all that wind and ash and cold, but would love to hear more and more, and of course, pics would me most welcome.
    BTW, what is going on SW Hekla? There is a small swarm at 7-8 km depth. Anything noteworthy?

    • I am officialy stating that my position on this swarm is *headscratching*

      If it had been closer to Haukadalur it would have reminded me of a swarm that took place a couple of weeks before 2000. But, right now I do not know.
      It is though in the end of the Sprungur area of the South Icelandic Fracture Zone, it could be tectonic only. And even as such they could be a sign of either increasing or decreasing pressure.
      I am keeping my eyes on the strainmeters.

    • Hekla CANNOT erupt now as I am going to travel on holidays outside of Iceland, and that would be hitting the really bad luck of missing its eruption! Damn it!

      Hopefully this is just strain at the eastern edge of the SISZ. And no eruption follows.

      I “pray” for an eruption only after the first week of September 🙂

  6. A fairly nice piece on the Siberian Traps. A bit to alarmist presenter, but otherwise pretty good.

    On a side note. It contains the largest set of Englishes I have heard in one documentary.

    • a good one, I always thought with all the volcanoes on the planet, they look like pock marks sort off, they go off at their own rhythm, keeps the planet ventilated and stable

  7. Evenin all,
    Typical… just when I`m in the mood for some serious volcanocafing it all goes quiet and my monitor decides that it has a dirty connection in the on/off switch, so refuses to work… I’ve resorted to Lizzie`s kindle which has a way better browser than our old laptop, but typing is an ass ache and there’s this predictive thing that keeps annoying me…
    Anyway thanks Ukviggen for 2 great articles, most enjoyable and informative thanks, I use a great realtime site for SO2 emissions at Popocatapetl which being ont kindle I don’t have access to… 😦
    Nuff moaning cheers all 🙂

    • Since you brought it up….

      NASA has an applet that came out about the same time as Giggle Earth. It’s called Nasa’s World Wind.

      It’s a bit of a bear, but you can use tiles from multiple sources and archives. One nice feature/difference in the Gurgle product is that Earthquakes are represented at the appropriate depth. Another “thing” that you can do with it, is to set up your own tile server on your local network and feed the tiles to the applet at LAN speed. (100 Mbps or whatever your network and system can handle.) It’s a great idea for educational environments where multiple student PCs on the local network are following along what the teacher is teaching.

      The downside is you have to be fairly adept at finding and getting gobal tile sets together. And you better have a patient Network/computer guy/person to put it together.

      It runs in a Java environment.

        • Dunno if he had a hand in it or now, but one of my fellow instructors who worked down in curriculum development learned Java programing in his spare time. He got out and hired on with NASA several years ago.

          We used to kill off lunchtime by playing Duke Nukem on a small LAN set-up. He was the king of well placed dynamite. Later, based on his technique, I adopted the tactic of hurling C-4 at Humvees in multiplayer BF1942 with the DC mod. The trick is finding a way to the roofs. I also picked up a bit of experience flying the Hind in that game. I liked it because it was the non-sexy helo. (lumbering and heavily armored) With a good gunner you could really mess up the opposition.

          Nexroth made a video of it. I am SimianSam. The name is a nod to Buckaroo Banzai, roughly equating to “Monkey boy.” There are other users of the moniker out on the net. I am not the gay dude up in Canada.

          “TheGit”, the guy in the Apache that bails out when under fire, gave me the additional moniker “Roof Monkey” from my tendency to throw crap from the roofs. That guy is bad ass with ballistic and guided weapons in game.

        • The trippy part about the gaming side of things….

          In real life, TheGit is a building manager, and spends most of his time fixing broken stuff. In game, he usually adopts an “engineer” kit and spends much of his time repairing in game equipment. (tanks, gun-mounts etc)

          In real life, I drive {forever}. In game, I tend to take on driving/piloting duties.

          I don’t know if there is some deep seated psychological issue at play or not. Generally I wind up with Git on the missile launcher and me tearing ass down the roads in a virtual 4 wheeler… with nitrous.

          Gaming is about as close as I’ll ever come to piloting.

  8. Seems like those quakes earlier today transfered a lot of strain towards Hekla. But no Hekla related earthquakes. So, the very rapid and unusually large strainincrease at HEK should wane off soon.

  9. Pretty much only FED works among the SIL.
    MJO is not showing much, HAU is on vacation and SAU is having a problem somewhere.

  10. Hekla, or no Hekla, that is the question.
    Mon nobler to draw an inch of lava against a sea of dispair…

    Time to go and hit the sack… even though it is a lovely stary night out on the deck.
    I do not think that anything is going to happen.
    Shleep well!

  11. Hello all, Got a story for ya. My fianceé and I have dicided to build a hot tub out of natural stone here in south-west Iceland. So I found the perfect spot for it to go and I started digging. I have a small hill up against a patio area that I had to excavate for the hot tub. After a few hours I hit a large rock. Then another next to it, yet another next to that. After cleaning around them it accured to me we have a wall under ground. I found an archeologist that happened to be digging at a site in my little village and asked for his opinion in the matter. After a short look he told me it was a “garden wall” and wasnt that old. 200 to 300 years old. He gave me his blessing and said I may remove it. I decided that this wall should be removed and used as on side of the tub. So the other day I started removing the stones, low and behold I found a two inch thick black ash layer half way up the stone wall. It was the 1226-1227 Reykjanestá eruption, other wise known as the ” Middle-ages layer”. So that means my wall was there before the eruption. Over 800 years ago. And yes I saved the ash in a nice little jar.

    And I found big worms there. The rock wall on the right I put in.

    • Well, that’s a boon. Now I have another Tephra set to chase across the Internet when I have some dead time. Thanks!

      VEI-4 → 1211 and VEI-4 → 1226. (GVP Data)

      Carl said (somewhat earlier on a different topic)

      That would also solve that odd magma… slabreduction.

      I like the choice of terminology.

    • HI Jamie good to see you. Now this clip has excited me! It is indeed a large earthworm. It certainly got me thinking . How do earthworms survive in volcanic soils. The particles are razor sharp not only could it damage outer skin but remember that earthworms burrow also by ingesting soil particles, digesting decaying organic matter and excreting the resultant waste soil. At what stage in the re-colonisation ( succession) after an eruption can earthworms survive? Icelandic worms must be specially tough to brave the coldest winters. Where do they hibernate? Are they specially adapted and so different from our UK worms? So many questions arising I feel a post coming on!!!
      Now the wall. If I found that in my garden I would have the urge to excavate more!! Again if it was in my garden I would guess it was an internal structure rather than a garden wall. The stones are fairly well dressed (Shaped). It is not very wide so not load bearing. I would think it is more like an interior barn wall, a cattle stall for instance. But of course I know nothing of Icelandic excavations or of your historical architecture. I love the proof of someone living just where you are so long ago. I wonder who they were?
      Will you send some ash for Spica ? Which volcano was it most likely to have been?

      • UkViggen! I got carried away by Jamie’s giant worm! Thank you for the post. I will now not skim over the satellite name when I see pictures from Space. The names now mean something to me. I sure as hell hope one of those super loos (Toilet/commode/John/WC/ ) do not come down anywhere near where I am standing!

      • Icelandic worms are plentiful in my garden here in south Iceland, they stay deep into the ground when there is frost, and when there is lots of rain they come near the surface. I guess worms do not hibernate. Bumble bees overwinter also in holes deep in the soil.

        The question is whether worms were here during the ice age or not. There could have been places that stood above the ice cap, or even at the edge of the ice cap. Or worms were introduced by vikings. Same mystery for many plants. The sorrels (súra in Icelandic) were discovered to have seeds burried under the glaciers, so they must have survived this way through the ice cap. Other species survived in nunataks. There could have been spots where the glacier melted to expose rock in summer.

        • It was more likely done in a poetic fashion.
          Bird shit.
          Birds carry plants and worms around the globe. The worms in the form of eggs.

          • Niceee 🙂

            Ice melts, followed by bird shit raining down, and then worms and flowers. Then present day Iceland.

      • Succession is another interesting topic in Iceland. First lava cools down after let’s say a few years or decades. That’s when lichens, and then moss starts to grow. This goes for centuries, as they will form soil within the ash and volcanic gravel. Sometimes some species can colonize that gravel after a few decades, like the Arctic Thyme, Sea Campion, Thrift, Moss Campion. They have big roots to search for water. Around Hekla or Veidivotn, some of these plants appear over the ash deserts.
        Trees are another story, they take many centuries, almost millenia. Usually in Iceland it’s lava fields over or around 1000 years that have trees, like in Reykjanes or Grimsnes. Places like Laki, where lava is around 250 years old, there are no trees, just moss and a few plants. This is because in Iceland climate is difficult, in a tropical country, trees would probably colonize a lava field earlier.
        In Surtsey, a new volcanic island, they saw the same succession. Tree seedling arrived some 40 years later. First plants mostly within 10 to 20 years. Moss after 1 year. Many plants first appeared around the nests of the birds because they depended on the nitrogen deposited in those places, while others not. I reckon that lichens, moss and many other pioneer plants can arrange for themselves all the nutrients they need. I have no idea where worms enter the picture.

        • Once again Irpsit you have added some very relevant and first hand facts. This is another reason why I tend to concentrate on watching Iceland. I can get my questions answered quickly with first hand knowledge and experience. That is worth 100% more value than book learning. Don’t get me wrong. I read. But in the past I have seen the disastrous effects on habitat caused by Rangers with amazing university degrees who refused to listen to farmer’s advice. Famers who have tended the land through many generations with knowledge passed down from generations.. Unless specifically written for a small area, most books will be very generalised and of course cannot cover small areas where the bedrock may be very different from the main area. eg a limestone outcrop in a mainly igneous area or vice versa. Soil depends on the bedrock or the sedimentary deposits such as sand dunes or mudflats

      • I have found worms amongst rocks underground, which means cavities with soil ? it gets cold here too like -12, I have been putting rocks in with soil since I have been gardening here, I never run out of worms come spring time, just a thought

        • the posts are a work in progress, I have a bitch pregnant driving me bonkers, so just write things down as I think will edit later, got some videos for it, in a way it is a blessing in disguise, like not getting to caught up with Bella

          • Awwwww! It was bad enough when our Meg had a false pregnancy. I dread to think what it would be like if she really had puppies. No chance of that now though. What sort of dog is she Ursh? VC seems to be having a puppy boom at the moment. 😀

            • Bichon Frise, an aunty of Bella was a bid like this and ended up chewing some of the pups legs off, getting carried away, I ended up living her be, out of a liter of 6, I had 2 viable pups, (I sold mum, desexed etc. and she is a perfect pet) which are perfect by the way and no problems there, one never knows with genetics, it just has me on edge a bid, I am getting to old for those capers

        • Oh that’s so interesting Ursh. Where are you? it must be up some height. What a very good practice. You really need worms for good soil. They improve the soil structure and drainage. That is another thought for my post. Most gardeners remove rocks!

          • I learned this when doing a bonsai course many moons ago, all the things I have beeen doing over the years, I like learning new things, I would be bored shitless if I don’t, I was told I should retire, rrrr not for me

  12. @Irpsit:

    No mails have arrived, I have emailed you twice on the email you use here to log in. Could you check your spambox?

    • hey Carl, I got it now, and I have emailed you the post. That email address you sent, I rarely read it. Its the one I always type to fill internet comment fields and so all spam goes there.

    • This is the latest published image from the Santiaguito webcam (1 per day)

      I wonder about the small plume on the right is it a PF or another vent further down?

  13. Hi UKViggen, thank you so much for your two enlightening posts! I have been digging around in those space images a lot, but never understood the difference between them. Now I will keep your explanations for reference!

    Also thanking the other commenters on sharing their thoughts and pics, eg Icelandic worm-monsters around a buried 900-yr-old wall in 800-yr-old ash beside Jamie’s house are unbeatable as an example for popular science interdisciplinarity 😉

    • Thanks! I suppose I got interested in the same way – ‘ASTER’, ‘MODIS’ etc are names that get bandied around quite a bit and I just wanted to know a bit more. To be honest there is an ENORMOUS lot more to know, and it all gets a bit alphabet-soup with all the acronyms, but I tried to keep it simple.
      I do like OLI and ALI, though – a family we know quite well has two boys called the same, and they are quite mischievous!

      • I must admit to have been to lazy to learn about the satelites… so before you wrote this I didn’t know how to keep my ASTER out of my MODIS. 🙂

        • Lurking is allready cool to beginn with. I am the one in need of some serious cool today. 🙂

          Edit: I have though on occation found him in the trash-can without ever really understanding how he ended up there. He moves in mysterious ways. 🙂

        • Eh… it happens.

          I was diverted from a normal call to deal with an ailing server in a different city. Servers take priority since they can take down an entire site, and that means loss of revenue. (You can work around a dead workstation, but if the server goes, nothing happens.)

          While driving, I heard the news blurb, and began thinking about “neat” stuff that could be done with that now closed school that is still yielding newly discovered graves. If an enterprising person were to put a wildlife camera looking out into the area, it might yield some spooky images over a few weeks as whatever becomes manifest trips the camera. Ya never know, might get a pic of a spirit along with the odd raccoon.

          Several years ago, I had the necessity of driving back and forth to Jacksonville about twice a month. (I was a “geo-bachelor” and my wife lived in Pcola with me stationed at Mayport). Marianna always struck me as a bit “odd.” After clearing Marianna headed to Jax, the interstate gets very dark and lonely as it runs through the swampland. (well, more swampy than west of there). At Marianna you had to pay extra attention since the SD and PD there like to get out and play on the Interstate, issuing citations and generally screwing with the people traveling by their “fine” city. (and if my suspicions are correct, ghost infested)

        • Ain’t happening in Florida right now. The temperature only broke on the way home when I droved up into a thunderstorm. More lightning than rain. Got a bit paranoid when I looked up and the sign read “Debris on roadway just before Avalon Blvd exit.”

          Turned out it was a disassembled large truck tire (shredded). That’s less hazardous that some of the stuff I have seen out there. Once, at the crest of the bay bridge, I spotted a recliner.

  14. Hi Uk Viggen

    Thanks for your 2 very thorough posts. A lot to discover. There is also another part ot this when using IR images (for instance) in a GIS software, but I am not proficient enough with the GIS (SAGA) to do much.

  15. And they keep coming:
    06.08.2013 19:26:15 64.023 -20.385 9.5 km 1.6 70.3 6.8 km WSW of Árnes
    06.08.2013 19:26:14 63.960 -20.155 9.7 km 1.7 90.03 10.2 km SSE of Árnes

    • Regarding the minor earthquakes in south Iceland, west of Hekla:

      These are tectonic, and not related to Hekla. I will explain.

      There are known faults, near Árnes, with sometimes big earthquakes up to M6 or M7. Historical strong quakes have occurred there. The two earthquake spots are along those faults. Even the IMO website shows this on its maps. Primarily, this has nothing to do with Hekla, but with SISZ, although it could affect Hekla strain.

      This place also had volcanism in the Pleistocene. Actually the whole of the SISZ seems to have minor eruptions every few millenia (last one occurred in Grimsnes around 5000 years ago). More evidence of recent eruptions occurs along the SISZ path, to the east, until Hekla.

      Usually, swarms in the SISZ only result in dike intrusions, because along the fault one spot moves north, while another moves south, but they barely rift apart. However, in rare occasions, magma can rise up until the surface. There is a paper that researched this but I forgot its link or title. This spot can also have an eruption eventually one day.

      • Problem is just that these quakes affect Hekla in some way.
        As they occur they normaly increase mountain straing readings. And about two weeks before the 2000 eruption there was a swarm of earthquakes in the same area as today.

        SIFZ is a very interesting area, and sometimes I think it is the key to the volcanism of Hekla, and also Hengill. But the mechanisms of it is poorly studied, and would need a lot of equipment to solve.

  16. Hi
    it’s been quite quiet under El Hierro recently, but there are still a few quakes a day. I have made the update on the earthquake density animation between July 1st and August 6th for the island.

    The first pass is with a moving colormap, the second one with a fixed one (at the max value). I have chosen a resolution of 150 x 150 m. There is another resolution available at 300 x300 m which is a bit different (more focused) and shows also that the grid parameter setting changes a lot the obtained results.

    There are clearly 2 very distinct zones, one on the west of the island with correlates with the last swarm ending around end of March 2013. To me it seems like cooling.
    The other zone is mainly under the island and is relatively more active (but not that much, a few quakes a day). This part is stranger because it is located very near older active zones (and the quakes seem to stay more on the outside of the old swarms).
    The colormap on the side corresponds to the number of earthquakes by area (see title to get the size).

    Data from IGN, NOAA, made on Gnu Octave, avconv for making the video

    • It just dawned on me… We just had a happy Finn singing… To restore order I give you the most depressed singer through all times. A Britt! (well he could be a Scotsman, Welch or Cargylefarian, but I am a Swede so I generaly would not know)

      And if you think that hairdo was weird…
      Here is the originals of the weird hairdos:

      • Hhahahahah, love your sense of humour Carl, what a choice, a pretty young blonde guy with make-up or else 6 depressives propping up a bar. ROFL.
        My personal choice here.

        GL Edit: Fixed link. If I missed it let me know.

        • It gets even better, the pretty young blonde guy in makeup is the deputy director of the Finnish murder squad 😉

            • Well… I do not know about that.
              The dark haired lady (Mia Hafrén) normally in the middle of the show asks (with a whip in hand) if anyone dares to get spanked by her… As far as I know I am the only one to have jumped up and screamed “Hell yeah!”
              I got both spanked on stage and hugged afterwards. I admit to a pangeant for strong women.

  17. OT: Simple Pleasures.

    Yesterday, I was rumaging around in the grocery store, talking on the phone (blue-tooth earpiece) to the wife, trying to come to an agreement about what she wanted me to get. {yes, I am one of those hated assholes}.

    I offered to make Fried Rice for supper, restaurant style. She noted that she could do the stuffed bell peppers that I had asked for a week ago. I went with her idea since IMO, it blows the doors off of my rice dish. Today, I had the one leftover Bell Pepper. She offered to make more. I swear, I am in pig heaven!

    Got a data-set to mull over (via an E-mail request), and one of my more enjoyed dishes being made by my wife (who is seemingly, no longer pissed off at the dog)

    My guess is the dog’s sheer terror at having thunderstorms around got to her.

  18. And some late night stripper music by the Hair band Warrant.

    Got my plot finished… but I’m not rolling it out here since I am not sure that the person who requested it would appreciate me scooping it before they use it for whatever purpose.

    So, you guys get Cherry Pie instead. 😀

    (It could have been worse, I could have linked Weebl and Bob.)

    If you are not really into that genre… there’s always Joan Jett.

  19. Everybody has a core. An essence that their life stems from. Strip away all the superfluous bullshit and you can find it. Some people have a certain genre of music that rings to that soul, that inner being. Some don’t. Go figure.

    I was sitting in my room listening to WZZQ (102.9) when I heard news that most of the member of Sskynyrd had gone down in a plane crash in North Mississippi. Later, some survivors of the band (not on the plane) made do with Rossington-Collins band. And eventually, Van Zant’s brother finally managed to get most of the sound of his brothers vocals close… and they “reformed” under the Skynyrd name. But despite their best effort.. they will never live up to the original.

    R.I.P. Steve Gaines and the rest of Skynyrd.

    Note: The link attached to the radio station is to “Post Toastie” by Tommy Bolin. A song that the DJ’s at the station absolutely hated since it screwed up their scheduling. It was always requested en mass and they were sort of obligated to play it. Think of it as a stab at them.

  20. Oh dear! Music! I actually like classical, Mozart mostly. These days I find Pop music unimaginative, synthetic and tinny. Rap I don’t class as music , it’s more like the sort of Bardic system of chanting poetry or a saga.
    Comments here are laughing at 1970’s hairstyles and Oh yes! The REALLY serious performers.” Music to cut your wrists by” as my husband calls it :D.
    Every generation has a music scene that reflects the ethos of that particular generation. I have been so lucky!. I was a teenager in the 1950’s and 60’s and was part of the huge change driven by a generation who had vision, money (Loads of jobs for everyone) and new freedoms.
    My father would have been so angry if he knew I was inhabiting the local coffee bar on Torquay sea front that was the proud possessor of a Scopitone juke box! These were a juke box that ran a 16 mm film along with the music. A precursor of the music video. The films were considered very risqué. They showed scantily clad young ladies gyrating and dancing . Dances then were wonderful. They all had names. The Hitch Hiker, Mashed potato and of course the Twist!
    Now I don’t know if it’s my advanced years but the young ladies looed in good shape without all the angst of diets and eating disorders. They were rounded in all the correct places and people then accepted a certain amount of flesh quite acceptable. Anyway the dances were workouts and kept your waist trim 😀 😀 here are two Scopitone films….. a typical Wonderful USA dance sequence followed by a song that has very happy memories of wonderful carefree summers.

  21. Well, the entity requesting the plots has had a chance to present them, and I need to do a rework to add a couple of reference point here and there, so here is the orig plot.

    It’s a convergent margin. Ruminate at will.

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