Mallow Posted June 13, 2011 Share Posted June 13, 2011 fixed Link to comment Share on other sites More sharing options...
okie333 Posted June 13, 2011 Share Posted June 13, 2011 http://wattsupwiththat.com/2011/06/12/earthquakes-and-volcanic-eruption-in-ethiopia/ Commenter Brian D. writes in Tips and Notes: With two 5.7′s just before the eruption, and a sat image showing a rather tall plume in the equatorial region, wonder how high and strong this bad boy is. Nabro has no known modern eruptions. Dubbi has 2(1861, 1400). Man, did this one come out of nowhere. Also h/t to Okie333 Link to comment Share on other sites More sharing options...
OHSnow Posted June 13, 2011 Share Posted June 13, 2011 Also sounds like Christchurch, NZ had an earthquake with some damage. Link to comment Share on other sites More sharing options...
Amped Posted June 13, 2011 Share Posted June 13, 2011 http://wattsupwithth...on-in-ethiopia/ It might be Dubbi then. It's pretty colse to the start point of the plume and if there if there is some wind shear the plume might be moving SW over nabro and then turning WNW once it gains elevation. Link to comment Share on other sites More sharing options...
Windspeed Posted June 13, 2011 Share Posted June 13, 2011 Visible satellite imagery of the eruption column: Notice the heavy ash base approaching Khartoum, the capital of Sudan. Will be interesting to see reports from there. Based on the appearance of the column, I would expect the city to receive significant ashfall: Link to comment Share on other sites More sharing options...
Derecho! Posted June 13, 2011 Author Share Posted June 13, 2011 Khartoum metro area has a population over 5 Million - who likely have not seen a significant ash fall before. And it's going to start falling with zero warning. Link to comment Share on other sites More sharing options...
Windspeed Posted June 13, 2011 Share Posted June 13, 2011 First official ash advisory; however, though it reports Dubbi volcano as the source, I don't believe it's an official confirmation until we get official reports from the ground. I still suspect this is from a vent near or within the Nabro caldera based on satellite observations. 20110613/0400Z VAAC: TOULOUSE VOLCANO: DUBBI 0201-10 PSN: N1335 E04148 AREA: ETHIOPIA SUMMIT ELEV: 1625M ADVISORY NR: 2011/01 INFO SOURCE: METEOSAT IMAGERY AVIATION COLOUR CODE: UNKNOWN ERUPTION DETAILS: ERUPTION STARTED AROUND 23UTC OBS VA DTG: 20110613/0400Z OBS VA CLD: FL150/300 N1330 E04145 - N1440 E03435 - N1625 E03430 - N1330 E04145 FCST VA CLD + 6H: 13/0900Z FCST VA CLD + 12H: 13/1500Z FCST VA CLD + 18H: 13/2100Z RMK: PLEASE CHECK SIGMET FOR CURRENT WARNINGS. NXT ADVISORY: 20110613/1000Z Link to comment Share on other sites More sharing options...
MJW155 Posted June 13, 2011 Share Posted June 13, 2011 On a scale of 1-10, how big of a deal is this? Link to comment Share on other sites More sharing options...
Derecho! Posted June 13, 2011 Author Share Posted June 13, 2011 Dubbi is really pretty far north of the origin of the plume, and I don't see any sign the plume heads SW and then turns NW. The probably picked Dubbi because it was recently (1861) active. Link to comment Share on other sites More sharing options...
Scott747 Posted June 13, 2011 Share Posted June 13, 2011 Another view - Link to comment Share on other sites More sharing options...
PottercountyWXobserver Posted June 13, 2011 Share Posted June 13, 2011 I'm wondering what the VEI is? 1-4 I'm assuming. Somebody said this was a stratovolcano? Link to comment Share on other sites More sharing options...
Amped Posted June 13, 2011 Share Posted June 13, 2011 Dubbi is to the NE, Nabro is closest to the plume origin. Link to comment Share on other sites More sharing options...
ineedsnow Posted June 13, 2011 Share Posted June 13, 2011 i cant believe this hasnt hit the major news stations yet! Link to comment Share on other sites More sharing options...
Windspeed Posted June 13, 2011 Share Posted June 13, 2011 I'm wondering what the VEI is? 1-4 I'm assuming. Somebody said this was a stratovolcano? Based on satellite observations alone, it's certainly larger than a VEI2. I don't feel comfortable stating anything beyond a 4 yet. We need time and ground observations to determine the ash's makeup and density. At any rate, we would hope for an ash plume of this size to stop growing. A sustained eruption continuing on for a day or more could be catastrophic for the people of northern Ethiopia and Sudan that are heavily reliant on cereal and grain production. Nabro is located near a very fragile ecological sector of Africa where destruction of food stuffs and shortages can quickly bring about an overwhelming humanitarian disaster. The Nabro complex is better described as a caldera or massive depression due to ground subsidence of overbearing rock where large volumes of material has been erupted from magma chambers in the past. It has shield basalt flows, cinder cones, dacitic and rhyolitic stratocones, domes and plugs. There is a smorgasbord of volcanism in this triangle of the East African Rift. Link to comment Share on other sites More sharing options...
greg ralls Posted June 13, 2011 Share Posted June 13, 2011 i cant believe this hasnt hit the major news stations yet! This is why I not only come to this forum when there is a big weather story, but when there is a volcano eruption, tsunami, earthquake - really just about anything. You guys always amaze me with how quickly the truth about things is discovered. Link to comment Share on other sites More sharing options...
TXWXCHX Posted June 13, 2011 Share Posted June 13, 2011 Based on satellite observations alone, it's certainly larger than a VEI2. I don't feel comfortable stating anything beyond a 4 yet. We need time and ground observations to determine the ash's makeup and density. At any rate, we would hope for an ash plume of this size to stop growing. A sustained eruption continuing on for a day or more could be catastrophic for the people of northern Ethiopia and Sudan that are heavily reliant on cereal and grain production. Nabro is located near a very fragile ecological sector of Africa where destruction of food stuffs and shortages can quickly bring about an overwhelming humanitarian disaster. The Nabro complex is better described as a caldera or massive depression due to ground subsidence of overbearing rock where large volumes of material has been erupted from magma chambers in the past. It has shield basalt flows, cinder cones, dacitic and rhyolitic stratocones, domes and plugs. There is a smorgasbord of volcanism in this triangle of the East African Rift. Amazing! Thank you so much for the succinct overview of this event... information regarding past events concerning this volcano appears to be sparse - however I did find this article alluding to recent magmatic intrusions in this specific area: http://www.bssaonlin...act/100/5A/1892 School of Earth and Environmental Sciences, University of Leeds, Leeds, England, LS2 9JT Areas of active volcanism contain elaborate velocity structuresthat complicate interpretations of earthquake source mechanisms.We examine the spectral characteristics of 805 earthquakes thatimmediately followed a large volume basaltic dike intrusionand associated silicic flank eruption of Dabbahu volcano inthe Afar Depression as recorded on near-source seismometers.We use these results to quantify the contribution of scatteringand attenuation to the observed spectra of low-frequency hybridand volcano-tectonic earthquake clusters from beneath Dabbahuvolcano and around the dike zone. We find strong variationsin the signal amplitude and frequency content of earthquakesrecorded at stations separated by as little as 2 km, causedby preferential attenuation of high frequencies depending onthe vantage point. These observations imply that there are largeimpedance contrasts near the cooling, solidifying, and recentlyintruded dike. We estimate the intrinsic absorption attenuationcoefficient, QI, and inverse scattering length, g0, averagedover a 300-sq-km area beneath Dabbahu. Our results are consistentwith the highest attenuation coefficients from studies of volcanicprovinces in Italy (, g00.1 km-1 for a signal at 2 Hz). The magnitude of thesetwo parameters indicates there are large impedance contrastspresent in the area due to the recent intrusion of magma andassociated fracturing. Link to comment Share on other sites More sharing options...
Windspeed Posted June 13, 2011 Share Posted June 13, 2011 Dr. Boris Behncke, a volcanologist and expert on Sicilian and Italian volcanoes has made some comments on this eruption: Firstly, about earthquake magnitude and eruption size – there is no simple correlation here. It depends on whether the earthquakes are directly triggered by magma movement or whether they are rather related to tectonic movement. In this case, I would bet that the earthquakes are related to tectonic movement (rifting), and thus they can be very big and yet the eruption might turn out relatively small. However, more violently explosive, voluminous volcanism is documented for the region, the most recent of these events being the 1861 eruption of Dubbi. It will be interesting to see which volcano this is after all – be sure that some volcanologists are already over it because there is great interest (from geologists, less so from the news media) in this region where there has been an impressive series of eruptions since 2005, all connected to massive rifting along the Ethiopian Rift. I suppose this is only the latest episode in this sequence of events. http://www.ees.roche..._GJI08_Afar.pdf http://www.agu.org/p...9JB000815.shtml http://www.enhans.or...n2011/Yirgu.pdf Link to comment Share on other sites More sharing options...
Roger Smith Posted June 13, 2011 Share Posted June 13, 2011 Here's a more recent satellite image: http://www.meteo.tn/htmlen/donnees/sat.php Meanwhile, on the Israeli government weather site, I found a 500-mb chart that shows Egypt in a trough in the westerlies so that one might speculate that when the ash reaches northern Sudan later today it may form eddies some of which will filter out into the southwest flow aloft towards Saudi Arabia, Iraq and Iran. Would therefore not be surprised if some ash heads west towards Chad and Niger, and some drifts north or northeast over next few days. Source still appears fairly active. The link for the Israeli weather site is: http://www.ins.gov.il Given that the last eruption of Nabro was quite prehistoric, we have almost nothing to go on here and this could turn out anywhere from low-moderate to major in terms of climate impact. Link to comment Share on other sites More sharing options...
Derecho! Posted June 13, 2011 Author Share Posted June 13, 2011 Toulouse VAAC advisory map: Link to comment Share on other sites More sharing options...
dan11295 Posted June 13, 2011 Share Posted June 13, 2011 Hasn't hit the news stations because of lack of info in general and its in an area of the world no one in the country cares about. Would expect some coverage as the ash cloud continues to expand. As stated above, significant ashfall over Sudan would result in a major problems beyound the political turmoil already present in that region. Link to comment Share on other sites More sharing options...
Master of Disaster Posted June 13, 2011 Share Posted June 13, 2011 This is why I not only come to this forum when there is a big weather story, but when there is a volcano eruption, tsunami, earthquake - really just about anything. You guys always amaze me with how quickly the truth about things is discovered. I find that fact about as fascinating as the actual event. I am not sure how some of these guys even discover this stuff. Link to comment Share on other sites More sharing options...
marsman Posted June 13, 2011 Share Posted June 13, 2011 USGS Volcano Disaster Assistance Program: http://volcanoes.usgs.gov/vhp/vdap.php Interesting group, wonder if they'll be mobilized for this event. Link to comment Share on other sites More sharing options...
Kmlwx Posted June 13, 2011 Share Posted June 13, 2011 A website I was looking at earlier is estimating the height of the ash at 13.5km - no clue on the reliability of said estimate. Still seems to be going based on satellite. Link to comment Share on other sites More sharing options...
Derecho! Posted June 13, 2011 Author Share Posted June 13, 2011 Looks like on the last few frames after fading a bit, the plume has gotten much larger at the source. Link to comment Share on other sites More sharing options...
Kmlwx Posted June 13, 2011 Share Posted June 13, 2011 Looks like on the last few frames after fading a bit, the plume has gotten much larger at the source. Which satellite site are you using? Link to comment Share on other sites More sharing options...
Ed Lizard Posted June 13, 2011 Share Posted June 13, 2011 I assume this is close enough to the tropics, if it winds up being of any size at all, to affect world weather ala Pinatubo? Link to comment Share on other sites More sharing options...
am19psu Posted June 13, 2011 Share Posted June 13, 2011 I assume this is close enough to the tropics, if it winds up being of any size at all, to affect world weather ala Pinatubo? The key is what the ejecta is composed of and whether it gets into the stratosphere. So far, it looks like the eruption is "only" up to 45kft, which won't get it there in the tropics. Link to comment Share on other sites More sharing options...
turtlehurricane Posted June 13, 2011 Share Posted June 13, 2011 A website I was looking at earlier is estimating the height of the ash at 13.5km - no clue on the reliability of said estimate. Still seems to be going based on satellite. All one would need for a rough estimate of plume height is the ir temp of the plume, an emission coefficient spectrum for volcanic ash, and a sounding in the region. Here's the sounding, from across the red sea in Saudi Arabia: http://weather.uwyo.edu/cgi-bin/sounding?region=africa&TYPE=TEXT%3ALIST&YEAR=2011&MONTH=06&FROM=1312&TO=1312&STNM=41024 Anyone got the other 2? Link to comment Share on other sites More sharing options...
dan11295 Posted June 13, 2011 Share Posted June 13, 2011 Not to get political in this thread but another likely reason for the lack of info is that Eritrea is essentially a closed state, ala North Korea. Like with Cyclone Nargis in Burma getting any info may be very difficult for that reason. Link to comment Share on other sites More sharing options...
Derecho! Posted June 13, 2011 Author Share Posted June 13, 2011 Which satellite site are you using? This is from http://www.sat24.com...f&lat=11&lon=40 Or, it could be a change in upper level wind direction, or the plume is at a higher/lower altitude and is moving in a new direction, I guess. Link to comment Share on other sites More sharing options...
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