Volcanoes of Saudi Arabia

Jurassic escarpment in central Saudi Arabia

Jurassic escarpment in central Saudi Arabia. Source: http://www.geo.tu-darmstadt.de/fg/hydrogeol/hydro_personen/khuffjilhminjurstudy.en.jsp

The rocky desert stretches as far as the eye can see: a fascinating vista, forbidding and seemingly unending. Distant hills shimmer in the heat and glare of the Sun. There is beauty here but it is on an inhuman and unearthly scale. The land has been baked bone-dry by many years of sun, heat and but little rain. Beneath, there is liquid to be found, but it is not water. Much of the oil which keeps our world moving was found here. There is another liquid down there too: molten rock.

Saudi Arabia is a land of contrasts, caught between different seas. To the west, the Red Sea. This side of Saudi Arabia is build on the ancient Arabian Shield, pre-Cambrian with some rocks over 3 billion years old although most is less than 1 billion years. There is old flood basalt here too, evidence of a tortured past. Along the Red Sea is the youngest part of the country: a low-lying strip of land less than 100 kilometer wide, a young scar in an old land. To the east, the Persian Gulf. Here the land becomes younger; this region is called the Arabian Platform, to distinguish it from the old shield. The oil is found at the eastern edge of Saudi Arabia. The Ghawar field, on the Persian Gulf, is the largest oil field in the world. Once, the tropical Tethys ocean was here. At times the Thetys became oxygen-depleted: the anoxic events lead to widespread die-off, forming thick layers of black mud. Over millions of year the mud turned to oil. The Tethys disappeared 10 million years ago but the oil remained: riches of the past. It is hard to believe that this unyielding desert was once a tropical ocean, teaming with life. How times change.

Two mountain ranges are stretched out along the Red Sea. The Hajiz mountains begin near the Gulf of Aqaba, and reach over 2 kilometers high; the range peters out near Jeddah. To the south are the Asir mountains, a higher range with peaks near 3 kilometers tall: the range reaches into Yemen where it becomes even higher. The mountains form the western edge of the Arabian Shield. To the west, they drop precipitously to the plain along the Red Sea (‘Hajiz’ meaning ‘barrier’), forming an escarpment. To the east, in-land, the drop is much more gradual. The Asir mountains are the wettest part of the Arabian peninsula, and some high areas receive an annual rainfall which would not be out of place in the UK. The rains have decreased over time. 5000 years ago, there was a major river flowing from the Hajiz towards Kuwait. Now, only a trace remains: the Wadi Bisha. Climate change -for the worse- is not new. There is a third mountain range, on the Indian ocean side, but located in Oman rather than Saudi Arabia. Near the centre of Saudi Arabia, east of the Hajiz mountains, are the remains of an ancient continental microplate. The microplate contains a memory of the formation and break-up of Pangea, and of the Rodinia supercontinent which came before. Continents tend to break up along old sutures, re-opening old wounds and leaving slivers in their wake.

Landsat images and ocean topography

A combination of Landsat images and ocean topography. From William Bosworth et al, Journal of African Earth Sciences 43 (2005) 334–378: The Red Sea and Gulf of Aden Basins

And now a new wound has formed; the Earth has stirred and the Arabian Shield has split. Half is stranded in Eritrea and Ethiopia, where it is called the Nubian Shield. The Red Sea has invaded the wound. Arabia became a peninsula, surrounded by the Red Sea, the Gulf of Aden, the Arabian Sea (part of the Indian Ocean), the Gulf of Oman, the shallow Persian Gulf (also known as the Arabian Gulf), and the Gulf of Aqaba. The split has formed the Arabian plate, the youngest of the main continental plates. The plate is slowly rotating anti-clock wise, pushing into and fracturing the Golan heights.

The Afar triple junction

The Afar triple junction. From http://www.see.leeds.ac.uk/afar/new-afar/geology-afar/structure-tech-pages/red-sea-aden-tech.html

The stirrings started in (aptly named) Afar, where the Red Sea, the Gulf of Aden and the Ethiopian (or East African) rift meet. Afar is a perfect example of a triple junction, distinguished by the typical 120 degree angles between the three rifts. The Afar triple junction is not actually located in the Red Sea, but on land in Africa, at the westernmost point of Djibouti. The three rifts have fragmented old Africa into three plates: the Arabian plate, Nubia (Africa), and the Somalian plate.

To see more evidence of this process, one has to look under water, an appealing thought in this dry land. The seafloor topography (see the Landsat image above) shows the Carlsberg Ridge within the Indian Ocean: this is the spreading centre that long ago split India from Africa and pushed it into Asia. Near Arabia the Carlsberg Ridge jumps north along a fault (the Owen Fracture Zone); it continues on the other side into the Arabian Sea, but than changes direction and enters into the Gulf of Aden. Near the Afar triple junction it disappears. A little beyond, in the middle of the Red Sea another spreading ridge can be seen. Back in the Indian Ocean, there is a subduction zone along the coast of Pakistan and Iran (the Makran trench, location of an M8.1 earthquake in 1945) but it is comparatively small.

The Owen Fracture Zone is a 1000-km long strike-slip fault. This is the meeting place between the Arabian and Indian plate. It is considered a transform fault (i.e. with sideways motion), with a relative motion of about 3 mm per year, which would make Arabia a remarkably slow-moving continent. In reality, the velocity of the Arabian plate is a more respectable, albeit still slow, 1-2 cm per year, but the Indian and Arabian plate have almost the same velocity and cancel each other out. Along the Owen Fracture Zone, on the Arabian side, is the Owen ridge, reaching up to 2 km above the sea floor. It is a sizable mountain chain, but fully hidden underneath the ocean.

The Red ocean?

The Afar plume, which initiated the break-up of this part of Africa, was active 27 million year ago. The Red Sea began as a continental rift which formed over a short period 24 million years ago. The sea first entered the basin about 20 million years ago. Sea-floor spreading along the southern Red Sea dates to about 5 million year ago, but only in the past million year has it started in the northern Red Sea.

The Red Sea is currently 2 kilometers deep: it is becoming a proper deep-sea basin, and is considered a proto-oceanic basin. But it took a long time to develop a sea-floor spreading ridge. The Gulf of Aden rifted at approximately the same time, but sea floor spreading started here already 16 million year ago: the Red Sea took twice as long. The Ethiopian rift is even slower: so far a few lakes have formed, but nothing more: it is widening at no more than 2.5 mm per year and the faults along its edges are now inactive. Before sea floor spreading can start, the rift has to drop below sea level. This is still a long way from happening in the Ethiopian rift.

The Red Sea has taken 24 million years to grow to 350 kilometer width. That is not particularly fast: it has grown at about 1.5 cm per year. The Gulf of Aden has a similar problem: although it had a 10-million-year head start in ocean-forming, it is still only 500 kilometer wide. The geological advertisements promised more than has been delivered. Why this reluctance to become an ocean?

The spreading rate of the Red Sea is four times slower than the Atlantic Ocean which is one of the slower mid-oceanic spreading ridges. The North Atlantic also had a very slow start, similar to the Red Sea, but it did in the end become oceanic. There is hope. The location of the Red Sea spreading centre is a difficult one. The spreading centre is trying to push Arabia north, but this runs into immovable Asia. Iran is giving it some space by moving north (pushing up its own mountain chain in the process), and the Red Sea has been able to fill the space vacated by Iran. It also tries to push Africa south, but Africa is a very big and very deep continent and is hard to shift. The Red Sea is thus meeting stiff resistance. It is truly a titanic battle between an irresistable force and not one but two immovable continents. The going is tough.

This may in fact be an excellent example of the ‘pull’ versus ‘push’ controversy: is continental drift caused by spreading centres pushing new crust out, or by subduction zones pulling old crust in? The Red Sea has plenty of northward push, but there is little or no pull acting on Arabia, and it isn’t working well. Arabia is becoming compressed. The Ethiopian rift is working in an east-west direction, trying to push Somalia out to sea, but this is going even slower. Continents apparently drift little without help from subduction zones. For continents, push doesn’t come to shove: push without pull won’t do.

The images below depict the evolution of the rifting, starting with a reconstruction of the continental arrangement of 30 million year ago, just before the Afar plume made its appearance. It shows how the plate separated and how the spreading ridges progressed into the rifts. The final panel shows what may happen in the future, at a time when the Persian Gulf has disappeared.

Reconstruction of the Arabian plate evolution

Reconstruction of the Arabian plate evolution

Reconstruction of the Arabian plate evolution, by Bosworth et al., Journal of African Earth Sciences 43 (2005) 334–378: The Red Sea and Gulf of Aden Basins. The final panel shows the expected layout 10 million years from now. This is subject to change!


During the time of the Afar plume, 26-28 million years ago, volcanic eruptions badly affected Saudi Arabia. The outpourings of flood basalts left lava fields covering large areas, which can still be seen in the landscapes inland from the Red Sea coast. Lava fields are called ‘harraat’ (singular: ‘harrah’), or ‘harrat’ if used as part of a name. This word occurs in many localities. The old ones dating from the Afar plume appearance are appropriately called the Older Harrats. Around this time the western and southern margins of the Arabian Plate were uplifted, creating what is now the Red Sea Escarpment and the mountains beyond. Volcanic activity diminished after this.

Volcanoes re-emerged 13 million years ago, perhaps in response to the collision between Iran and Asia. A series of haraats were deposited: Uwayrid, Khaybar, and Rahat, 10-12 million years ago. These are, for obvious reasons, called the Younger Harrats.The Younger Harrats are typically less than 300 meter thick. Eruptions continued along the newly formed continental edge until the present day, albeit weaker than before.

The main harraats in Saudi Arabia

The main harraats in Saudi Arabia.
From M.Moufti et al. Journal of Asian Earth Sciences, 62, 253 (2013)

The most recent documented eruption of a volcano in Saudi Arabia was in 1256, near Medinah (known as Madinah in Arabic, which is also how it is pronounced). It came from a fissure within the extensive Harrat Rahat. The event started on June 5th with an earthquake swarm. The strongest earthquake hit 4 days later and it was followed by fountaining from a rift, only 19 kilometer southeast of Medinah. Eye witnesses, albeit paraphrased and reported 300 years later, give a vivid account of the events (from Camp et al., 1987, Bull Volcanology, 49, 489 ):
For days the volcanic eruption was preceded by many great earthquakes which occured in Madinah at the beginning of Jumad-Al-Thani (Monday 1st June 1256). At first the movements were slight and not all of the residents of Madinah town felt them. On Tuesday, the second day of Jumad Al-Thani, the earthquakes became stronger. On Wednesday, in the third part of the night, the greatest earthquake occured, which frightened the residents. The earth tremors continued throughout the rest of the night. On Friday, a major event occured, when the ground and ceiling of houses were shaken. Eighteen earthquakes were recorded during this day. […] After the main earthquake was felt in Medinah at midday, fire appeared associated with black smoke clouds which accumulated in the atmosphere. The greatest fire covered the horizon to the east of Madinah. […] The lava flow carried along its way gravel, stones and trees. It was like a red-blue boiling river, with thundering noises. The lava flow moved toward the north of Wadi Eheline. The light of the fire was seen in Makkah, Busrah, and Taima. The historians wrote that the fire continued for three months […] The lava flow descended on the rocky ground and was as high as a long spear above the ground level […] When the lava flow came to a complete stop […] it created a dam that formed a great lake in the rainy seasons (Lake Al Habas).

(The ‘third part of the night’ means the hours before sunrise, the night being divided into three parts. ‘High as a long spear’ indicates that the lava flow was a couple of meters thick.)

The eruption formed six (unnamed) scoria cones along a 2.25-kilometer rift. Over the next 52 days several lava flows extended 10 kilometers from the rift, and one much longer flow came to within 7 kilometer of the old city, within the area of the current suburbs, turning north just in time and sparing the city. About 0.5 km3 of lava was erupted. The lava is a mixture of two components, one of which had fractionated in the mantle and came up rapidly, and one which had been stored in a higher-lying magma chamber in the crust and included some crustal melt. The presence of both a magma chamber in the mantle and one in the crust is an interesting complexity.

 Medinah and its 1256 lava

Medinah and its 1256 lava. Source: Google earth

The 1256 flow field is located near the northern edge of the Harrat Rahat: this lava field, of which the 1256 eruption was the latest twitch, stretches from Medinah to Makkah, measuring 300 kilometers tip-to-tip, with an average width of 60 kilometers. It contains 644 scoria cones, 36 shield volcanoes and 24 domes. At times the lava flowed over the escarpment onto the coastal plain. The activity migrated north with time, and the main forcus is now south of Medinah. Future eruptions from the Harrat Rahat will probably occur in this region, and eruptions close to or within the city cannot be excluded. In fact another minor eruption occured in 641 producing several aligned cinder cones southwest of the city, lighting up the night sky.

Near the western margin of Harrat Kishb, 100 km southeast of Medinah, is the 2-km wide Wahba crater which was probably formed in a phreatic explosion. It is the largest crater of its kind in Saudi Arabia. The date is not well known but it has been estimated as 10,000 year ago, with a minimum age of 4,500 year. The crater provides a spectacular sight, but being a hole in the ground, is only visible from close-up.

Geothermal activity is also present. Hot springs with temperatures ranging from 50 to over 100 degrees occur on and off the escarpment, mainly south of Jeddah. Fumaroles are present, e.g. on Harrat Ithnayn and Harrat Khaybar, but the steam may only become visible during the coldest time of the year. More worryingly, weak fumaroles are present along a 3 kilometer line close to Medinah, coincident with occasional earthquake activity. This area is closely monitored; there is currently no indication of increasing activity.

Bedouin sources indicate that there was an eruption from one of the cones of Harrat ‘Uwayrid volcano, midway between Medinah and the Sinai, around the year 640. It is not known precisely which cone erupted and the eruption appears to have been a minor one.

Location of the 2009 swarm

Location of the 2009 swarm. Earthquakes are indicated by the yellow dots. From Koulakpov et al, Solid Earth, 5, 873–882 (2014)

In April to June 2009, in a previously seismically quiet area in Harrat Al-Shaqah (also known as Harrat Lunayyir) 150 kilometer northwest of Medina, an earthquake swarm occured similar to that in 2014 in Bardarbunga. The figure shows the distribution of the quakes, along the linear dyke: it was 20 kilometer long, and came up from more than 20 km depth at the southern end to less than 7 km at the northern end. An 8-km-long surface rupture occurred during this event, with a vertical offset of 90 cm between both sides. The 2 meter thick dyke was filled with an estimated 0.13 km3 of magma. The magma managed to get to within 2 kilometer of the surface but the last bit of crust was too rigid and it failed to break through. For a while an eruption was considered possible, and as a precaution 20,000 people were evacuated. The event happened underneath an existing lava field which may have been erupted around the year 1000.

Jabal Abyad, Jabal Bayda and Jabal Qidr

Jabal Abyad, Jabal Bayda and Jabal Qidr form a vivid contrast

A natural marvel is the area known as the Black and White Volcanoes. It lies within Harrat Khaybar, due north of Medina. Two volcanoes here have erupted a cream-white lava, a felsic silicate called comendite. Nearby is Jabal Qidr, a dome of pitch-black basalt, a hawaiite. The division between the two lavas is stark. There are neolithic stone walls on the black volcanic slopes, and some of them have been overtopped with lava. There may have been as many as seven eruptions since people started building the walls, and Jabal Qidr may have erupted as recently as the year 1800. The two white mountains, Jabal Abyad, at 2,093 meters and Jabal Bayda at 1,913 meters, are the two highest volcanoes of Saudi Arabia. (Both words mean ‘white mountain’, one with the female and one with the male adjective.) The pairing would have been a wonder of the world, but it is in an isolated and desolate region, difficult to reach. The contrasting lavas have come from a single magma chamber in the crust underneath, which is extremely stratified.

No less wondrous are the gems found in the area. Beautiful peridots, a form of olivine, are embedded in the basaltic harraats. The peridots from this region are of a pure green, a precious colour in the desert: the peridots are highly valued. The most recent find was in Harrat Kishb.

The rift itself, now deep below the sea, is also volcanically active. A number of volcanic islands have formed within the Red Sea, near the Afar triple point. On 30 Sept 2007 there was an eruption midway between both Red Sea coasts, on the small island of Jabal al-Tair. In 2011 and 2013 there were Surtseyan-type, submarine eruptions in the Zubair group of islands, further south along the coast of Yemen towards Djibouti, where new islands emerged from the sea. Volcanic activity further north along the younger Red Sea spreading centre is much less, although there are deep hydrothermal vents. There is no sign that the extensive flood basalt activity prior to the opening of the Red Sea will one day resume. Lesser, intermittent activity remains common, however.


The potentially active volcanoes within Saudi Arabia are offset from the Red Sea spreading centre by about 100-150 kilometers. One can speculate why this is. Around Medinah, the oldest lava fields are 2 million years old, but these are in almost the same location as the new activity. Over that time, the Arabian plate has moved by perhaps 50 kilometer due to the widening of the Red Sea. The volcanoes have moved with the plate. This means that the magma is located in the continental plate and does not come from the oceanic Red Sea spreading centre. The felsic lavas confirm that the magma has been stored in the crust and is not currently coming directly from the mantle, but the predominant lava is still basaltic, i.e. originally derived from the mantle.

The magmatic activity may be due to local crustal extension. Alternatively, the magma may have been emplaced at the start of the seafloor spreading, but this begs the question what kept it from cooling. A sub-crustal flow of magma from the triple point has also been suggested, but the level of activity does not seem to decline with distance from Afar which argues against it. Crustal extension therefore seems most plausible. Especially the northern-most Red Sea does not yet have an active spreading centre, and without new oceanic crust being formed, the movement of the Arabian Plate has to be accommodated by the crust, leaving a line of weakness around Medina.

An interesting suggestion is that the line of the Younger Harrats, which is under a slightly different angle to that of the Red Sea, is a separate rifting event. There seems little direct support for this, but if this is correct we may end up with two parallel oceans, separated by a sliver of Arabia.

State of the nation

At the current time, volcanic eruptions in Saudi Arabia tend to be minor to medium in size. Several eruptions were reported about a millennium ago but there has been little activity since 1256. In the empty desert, more recent eruptions may have been missed. An eruption in the near future is not unlikely. Although it would probably not be a large event, Saudi Arabia could still be supplementing its oil with liquid rock. Just remember the word ‘harrat’.


/ Albert
With thanks to Samira Alharbi

95 thoughts on “Volcanoes of Saudi Arabia

  1. Very nicely done Albert, good graphics and good explanation of volcanism and rifting in this intriguing part of the world. Cheers!

  2. Awesome read. The geology and tectonics in this region is quite befuddling, complex, and astounding. It’s a bit unfortunate that the area is difficult for researchers to access, largely due to civil unrest, pirates, and the many other problems that come with the middle east these days. Saudi isn’t so bad (at least in terms of unrest), but Yemen and the red sea are another story.

    Yemen specifically has had some truly massive explosive eruptions, which likely occurred during the time it rifted off of Africa, although these are very much unstudied due to this lack of accessibility.

    • Last time I went through there we didn’t have any problems. Of course, that was years ago and we did have manned gun crews on the .50s.

  3. Thank you Albert for a good read, it must have taken ages to research this one.

    I would though like to point out that the rapid formation of the Jubair group may change the Red Sea in interesting ways as they continue to expand. As far as I could find out when I wrote the articles about the 2011 and 2013 eruptions none of the islands is old, perhaps not more than 3000 years (but the dating is “iffy”).

  4. You know when I first went through the article I thought-Mars? oh, wait…
    Very interesting geology there. good job…

    • Valid point… the terrain is a bit similar in appearance… Sort of like Newark…

      (Sorry, but I’m just not that fond of Jersey)

    • The movie The Martian was filmed in Oman. So this is Hollywood’s Mars.

      • That did detract from the realism,it looked like Jordan(2000 Red Planet Movie) or similar,Maybe a CGI landscape would have been more effective,Mars has features that are out of proportion to earth,such as Olympus Mons and Valles Marineris.The documentary about what the earth would look like without the oceans may have been a better look?

        • Perhaps. Much of the movie takes place in the northern plains of Mars, which consists of sedimentary layer on top of a old, cratered surface. A desert river bed may well be the closest we have on earth. Oman doesn’t quite look like it (mountains seemed too steep), on the other hand it wasn’t a bad choice. CGI would have been expensive, I expect.

          I am looking forward to the movie ‘The Venusian’ except with its atmosphere the actor wouldn’t last long. His vehicle would corrode to nothing in much less than the 90 minutes required for a full movie. So perhaps I’ll settle for the movie ‘The Arabian’. The scenery would be oscar-worthy.

  5. Spooky, there was a 4.8 in the middle of the southern Red Sea within the last hour (22 43 UTC).
    Between Eritrea and Saudi Arabia.

  6. OT… and yes, I am a dog person.

    “Anyone who owns a dog is familiar with the “gaze”—that hypnotic, imploring stare that demands reciprocation. It can seem to hold a world of mystery and longing, or just pure bafflement at what makes humans tick.

    It turns out that the look of mutual recognition between human and dog reflects thousands of years of evolution, a bond programmed into our very body chemistry. Last spring a research team in Japan discovered that both species release a hormone called oxytocin when they look into each other’s eyes—the same hormone released when a human mother beholds her baby.”

    Read more at: http://phys.org/news/2016-03-explores-prehistoric-relationship-humans-dogs.html#jCp

    Note… the article says “oxytocin” not Oxycontin. This is also the same drug that some idiots steal from veterinary offices thinking it’s the other.

    BTW, if you wish to go stare at a dog now, be careful. Some can construe a direct stare as a threat. Especially if you are staring down a self perceived alpha.

    • 😀 😀 😀 Oxytocin induced lactation in mammals and is even used on human females who experience difficulties to start breastfeeding. Now imagine those eejits high on oxytocin and gawd knows what else together with their dogs… :mrgreen:

      • Well, the running joke around here was that they needed to look for cuddling skateboarders with weepy nipples.

    • Staring at a dog is a good way to offend it. If you are trying to say hello to an unfamiliar dog, you need to turn your side or back to it and offer the back of your hand for it to sniff (but not too into its face at first). Absolutely no looking at the doggy’s eyes. First time I tried the above, it was on a gigantic pit bull thing tied up outside a shop and blocking people’s way in, worked like a charm – got the monster wagging its tail and shifting herself out of the way. The moment I forgot, and looked at her, down went the tail and flat went the ears.

      • Ears back, watch out…

        The critter I have is quite happy right now. I picked up a bovine femur and tied it to a twine and drug it around the yard before concealing it in a bush. When I let the critter out he did a quick scent run and found the bone. He is a happy camper right now. When he found it he had his head held high and tail wagging quite energetically.

        Mines a Lab/Pit mix. He has a sizable “generic dog” build. Quite muscular and well defined… if a bit hyper. Has a nice stag red coat, but is almost invisible in the dark. When I call him in at night I have to look for the blue eyeshine with a flashlight. Seeing as it’s my dog, the flashing white teeth underneath the eye-shine doesn’t scare me. Now if I were an intruder… you don’t even hear him until he is just about on you. His only vocalization is a low growl as he goes in for a hit.

        What is more fun than thinking about what would become of a potential intruder… is that if they flee over the neighbors fence, that’s not going to be pretty, he has two Great Dane/Pit mixes.

        • My Springer, Rollie has gotten a “Snood” covering for his head and ears. I put it on today, he gave me that “pitiful” look he gets when he
          thinks he is in trouble Then he realized that with the Snood comes
          Dog dinner.!! OH BOY! so he his happy that his ears don’t drag in th
          dog food and the Snood means food..
          Got word today I may have a shot a flying single engine airtankers.
          The issue has been training-now the company has a Two Seater
          AT805 ordered it will arrive shortly..

          • I wish you best of luck, and keep the shiny side up! (Well, up where appropriate.)

            Hmm… same general engine power class as a P-51 with almost twice the wing area… that has got to be a seriously nimble critter. No wonder they use the term “tractor” in the company name.

  7. O.T.
    for general knowledge I’d like to share this brand new article on a dome like feature driven from volcanic gas releasing discovered in Naples gulf, 5 km offshore, just in front of the harbor, midway from Ischia – Vesuvio – Campi Flegrei.
    The dome (5×5.3km) elevates 15-20m from seafloor and present active gas and fluids emissions, cones, craters and so on. Water column gas and T°analysis and other interesting data are well presented.
    Authors from CNR-INGV.
    The article has been distributed under a Creative Commons CC-BY license. You may reuse this material without obtaining permission from Nature Publishing Group, providing that the author and the original source of publication are fully acknowledged, as per the terms of the license.


    • Perhaps Ischia – Vesuvio – Campi Flegrei are all just ring structures for a system that started life about 40kyr ago but never got around to having a main event…

        • It is, but the reply function is pretty bad on this blog. I meant this as a reply to dithox – he mentioned using tinypic, and I suggested Imgur as a better alternative. Unfortunately, the reply got stuck up here instead of down in reply to a response where this made sense.

          • And that made a lot of sense 🙂

            I just had to ask to make sure your account was secure.

            Imgur is pretty good. But, in this case the best thing would have been to just post the link directly to the image-url.

    • No it would not be the same.
      You either need deposites of readymade CO or bedrock inducable to produce it.

      • So the Professor may find that the US is different to Gujarat:

        ‘The researchers discovered the connection between CO emission and earthquake by analysing satellite remote sensing data collected around the time when a 7.6 magnitude earthquake shook Gujarat in western India nine years ago killing about 20,000 people and rendering thousands homeless.

        Singh said that CO levels were taken by an instrument onboard NASA’s Terra satellite — launched in 2009 — circling the earth in a polar orbit at a height of 705 km. The instrument measures CO concentrations at different heights and also computes the total amount of the gas in a vertical column of air above the earth surface.

        Analysis of the satellite data showed a large peak in CO concentrations during January 19 and 20 — a week before the main earthquake event. On January 19, the total CO in the vertical column was also higher than usual. After the 26 January earthquake the concentration of the gas dropped.

        According to the scientists, CO gas is forced out of the earth due to the build up of stress prior to the earthquake “influencing the hydrological regime around the epicentre.”

        Singh said an anomalous increase in land surface temperature a few days prior to Gujarat earthquake — as inferred from the data of NASA’s other satellite MODIS — is also related to the CO emission. “The increase of column CO and concentrations of CO may have enhanced the land surface temperature,” he said.

        “The anomalous changes in CO concentrations prior to the main earthquake event and enhancement of temperature of the earth surface observed from MODIS satellite data give an indication of coupling between land and atmosphere,” the scientists report. Singh said observation by other researchers of a sudden increase in water vapour in the atmosphere and changes in the ionosphere a few days prior to the Gujarat earthquake all seem to be connected.’

        • The esteemed professor in Gujarat has also invented a time machine methinks. The satellite was launched in 2009 and that the earthquake he measured with the satellite happened 9 years ago?
          Is it just me that does not get it?

          Also, a few years ago it was a big hubbub about the Tohoku earthquake and gases, it was all disproven in a short time frame. I do not think that gases is the way forward on big earthquakes. I have a couple of ideas, but this is not the time and place to discuss that.

        • The link I gave on 2.3.16 two posts back has changed. I mean up until yesterday it was still showing half of alifornia turning black as the CO levels seemingly jumped 100X or more in places. Now though it seems the levels have been ‘adjusted’ and show what I would assume is a more normal or explainable by weather phenomena sort of levels. Maybe it was a glitch eh. Did anyone else see that?

          • With California, it’s likely more related to the number of cars on the road.

            The 405 is really as wide as depicted in the spoof movie. Usually, it’s packed. In reality, the aircraft’s wings would have been shredded by the poles. There is also a possibility that the pavement could not have withstood the wheel loading.


          • Hello!

            There was an instrument malfunction in a satellite that caused it all.
            But, California normally has raised gas levels from cars as Lurking said.

          • Thanks Carl for that information; malfunctioning satelites eh, who’d have thought. The CO levels after adjustment do look like what I would consider normal and can easily be explained by vehicle emissions. Not that I’m an expert of course.
            It did look very impressive at the time, before the ‘adjustment’. That earthnullschool map is very good, you can zoom in and wherever you click the pointer it brings up a value and co-ordinates to a very high resolution. One spot I saw before the later adjustment showed a value of around 150 ppbv (‘normal’ background) before midnight on the 26.2.16. A few hours later it was 45000ppbv at the same spot (at the wal mart hyper market in frezno). I didn’t want to cause a fuss earlier (before adjustment) so I didn’t elaborate on what I saw, as I say again I’m not an expert, and the disclaimer on the map says it’s just for research and not a diagnostic tool.
            However, a satelite malfunction is a much easier explanation to deal with!
            Just as well I’m not an expert 🙂

      • I had seen the report but dismissed it. If you want to see gasses forced out of rock, CO would not be the one to look for. CO comes from fires. It was said to happen a week before the quake – lots of other things could have caused it. There are daily maps produced of CO emissions in the world. The satellite was launched in 1999, by the way.

    • OK so Volcano Discovery isn’t apparently the most reliable of sources, but a figureof 1000+ dead from Nyiragongo’s two 20th century eruptions? Has anyone got definitive figures – I thought the official count was 75-100 in 1977 and around 50 in 1994

      • That would be those that died directly from the eruption.
        There is though a higher number that is supposed to take into account displacement and other secondary effects.

        • Thannks, Carl. Guess the fact of the area being in or near a war zone more or less continuously since about 1960 doesn’t help matters

  8. Same hemisphere, but the other side of the planet.

    Appears that Volcan Colima is getting a little iffy

    From University of Colima:

    Edited away the link since it did not work.
    Just use regular links to the picture you wish to show and it should work.

    • oops, that did not work. is pastebin a good place, and then refer to that?

    • Drop the whole link in here and I can go and set it up. I tried reconstructing the link but got a “La página que busca no existe” error.

      Personally, I tend to use tinypic.

      • tinypic it is then. I don’t run a webserver yet, hence the file://…

        • Do not use that prefix on a link in here. It does not work.
          Is that image visible at a site that is up and running? If so, just copy paste the image-url and it will show here.

      • bummer.

        tinypic gave me 503 error, after wading through all the popups. guess I need to restart apache.

        The seismo looks kinda like the Fuego charts, but not quite as thick.

        However, there is a cold front coming through, so the webcams only show the clouds…

          • I can’t. Gmail has a @#$ fit when accessed from multiple continents. It will have to be relayed to me via the back channel.

    • If anybody was in a position to see it comming, the plant operators should have had the best equipment view.

      I would love to have seen the well pressure data leading to that event.

      • I bet that the guys running the place have a good assortment of equipment around the area. Mainly seismometers and GPS-stations. I would though be surprised if they had any borehole strainmeters.

        Strainmeters are splendid, but drilling a hole separately to install one is cost prohibitive. You normally make one as an old borehole is decommissioned (20 to 35 years into operations) or if you get a “dry” hole. And even then it is seldom that people install one. I am of the opinion that strainmeters are wonderful and should be employed far more around volcanoes.

      • I would hope that they at least have an inlet manifold pressure recording device. A gifted enough engineer could work backwards to the steam production rate and get a handle on what was going on down in the formation prior to the nearby eruption.

    • From NDVP#2

      “Momotombo volcano is one of Nicaragua’s most familiar landmarks. It is a somma volcano, meaning it has grown on the edge of the caldera of a mainly collapsed, previous edifice; Monte Galán. It began growing about 4.5 kA BP at the SE end of the Marrabios Range and the symmetrical cone has now attained a height a.s.l. of 1,297 m with a prominence in excess of 1,100 m. If we only take into account the portion above the 400-m isoline, the edifice has a volume on the order of 3.5 km3.”

      And, if you do a quick back of the envelope calculation, that’s an average of 777,777 m³/year to build an edifice of that size in the allocated time.

      I’ve stated before, that they best defense agaisnt volcanic hazards is to not be there when it does it’s thing. The city of León is a good example of this.

      “The city [León Viejo] was not destroyed by the 1610 quake, however due to the damage caused to the infrastructure and the seismic activity, the settlers held a referendum and decided to relocate the city to its present location, about 20 miles to the west. Nevertheless, the old city was gradually buried by the continuous expulsions of ash and volcanic stone coming from Momotombo, and by lake sediments”

      With a current Metro population of 389,600 [León]… this was probably a really good idea. León Viejo is about 8.6 km from the summit.

      • Momotombo is impressive, but for those who haven’t seen my ramblings on here before, I think it’s quite interesting to point out that Klyuchevksoy in Kamchatka has similarly been made in 6000 years. The difference is that Klyuchevskoy is well over 4x the size of Momotombo, truly a ridiculous volume and growth, especially when considering that there is likely a lot of magma that is not erupted.

        I don’t mean to point this out to say Momotombo isn’t impressive with how large it has grown in such an insanely short time, more just wanted to point out another similar scenario of insane geology.

        • Thank you, and a quite valid observation!

          Addendum to my earlier comment, Old Leon is roughly left of the “p” in the word plume in the satellite image above.

  9. Thanks Albert.

    I couldn’t help but think of Dr. Doolittle’s push-me pull-you when you wrote,

    For continents, push doesn’t come to shove: push without pull won’t do. 🙂

    • which continent would be the gazelle and which the unicorn? In the book they are now one continent. Somehow continents lack the grace of a gazelle.

    • That does look nice. It seems not a single swarm but activity at several location and very different depths. There were three deeper quakes (8km or so) right in the centre of the caldera, in a region that was quiet during the Barda eruption. Those may be the ones to look at. The rest seems just movement along the ring fault.

    • Not as nice a plot but perhaps this will do. Te bottom two panels show the location of the M2+ quakes since December, in red. The black dots show the quakes from the 2014/15 eruption: it is in general the same area but not identical. The top two panels show today’s swarm(s). Note the ones from the centre of the caldera. They are at 8-10km depth and perhaps form a bit of an east-west line.

      • I modified the source code from baering just to focus on Bardarbunga (as well as other areas of Iceland)

        Changed links to png files to the jpg files.

      • Bottom charts show a shallow intrusion surely?latest batch to small and too scattered to really indicate anything?

    • Crypto dome is not visible on the surface?Once it has breached the surface it would be a dome,would it not?😊

      • To my understanding, a cryptodome can very well be visible as a bulge on the surface. Crypto just means the magma has not yet breached the surface. If that happens and lava is extruded, it stops being crypto and turns into a lava dome. Please correct me if I’m wrong.

          • It could postdate the crater but this is hard to judge. One option is ice melt below the surface: at these temperatures, water takes the role of magma, but as it is heavier than ice it tends not to break through the surface. In fact it is possible this is an anti-dome: it is what was left after the surrounding area collapsed when deep ice melted and sank. Or combine the two and suggest that the sinking water pushed up an area in the middle. It is difficult to judge the underground geology (should that be asteroid-ology?) (I wouldn’t dream of shortening this to aster-ology) from what is seen from above.

            Thank you Albert, that cost me a keyboard after a massive coffee-spritz!

    • I would have to believe this is closely correlated with the rate of subduction on the North Island as well, which would likely be at least partially responsible for the prolific volcanism on New Zealand’s north island.

  10. The earthquake swarm in the straits of Gibraltar seems to have picked up again. It started with an M6 in January. The second strongest quake in this swarm was this morning. The location is intermediate between the African coast where there was a similar swarm in 2004, and hte spanish side which had an M7.4 in the 1950’s.

  11. The Friday update will be up a bit later today, it’s 90% completed but I’ve had to stop writing for the moment. I’ll get it completed after I eat some dinner.

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