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Alu-Dalafilla

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  • Country
  • Volcanic Region
  • Landform | Volc Type
  • Last Known Eruption
  • 13.793°N
  • 40.553°E

  • 578 m
    1,896 ft

  • 221060
  • Latitude
  • Longitude

  • Summit
    Elevation

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Most Recent Weekly Report: 19 November-25 November 2008 Citation IconCite this Report

During 19-24 November, the MODIS satellite continued to detect thermal anomalies over the area near Dalaffilla and Alu volcanoes from the eruption that began on 3 November.

Source: Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts Team


Most Recent Bulletin Report: December 2008 (BGVN 33:12) Citation IconCite this Report

Lava flow-field size unchanged for months; thermal alerts ceased 28 December

The eruption that began on 3 November 2008 (BGVN 33:10) significantly slowed or ceased prior to January 2009. The region is the scene of sporadic fighting, thwarting direct reports from people in the field, and forcing greater reliance on remote-sensing imagery.

Looking at Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite system images for 19 December 2008 and 4 January 2009 (figure 9), Matt Patrick found little significant change in the shape or area of the lava flow field since 8 November 2008 (see image in BGVN 33:10).

Figure (see Caption) Figure 9. Satellite ASTER images over Dalaffilla and Alu volcanoes on 19 December 2008 and 4 January 2009. Shown are nighttime thermal images (band 14, 11-micron wavelength) showing flow to the NE from a fissure or fissure system between the volcanoes. Courtesy of Matt Patrick.

Thermal alerts over the eruption site reported by the MODVOLC system were absent after 28 December 2008 (figure 10) through at least early February 2009. At the start of the eruption (identified on 3 November at 1920 UTC) there were 148 alerts in a circular pattern well extending outboard but engulfing the densest area of alerts over the main lava field. Following the initial eruption, the alert pixels concentrated primarily on the lava flow. No thermal anomalies were detected for at least several years before the November eruption.

Figure (see Caption) Figure 10. A plot of the maximum number of daily MODVOLC thermal alerts at Dalaffilla during November-December 2008. Courtesy of the Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System.

NASA's Earth Observatory (EO) released a true-color image captured by Taiwan's Formosat-2 satellite (figure 11). The image caption, by Ralph Harrington, noted that fresh flows from the recent eruption appear darker than the older weathered flows. Lava spread from the fissure several kilometers to the NE, as well as S and SW. The image also appears to show spatter cones associated with the fissures.

Figure (see Caption) Figure 11. A Formosat-2 satellite true-color image (enhanced here) acquired 25 December 2008 of the Alu and Dalaffilla portion of the Erta Ale range of the Afar region. FORMOSAT-2, developed by the National Space Organization (NSPO), launched in 2004 with 2-m panchromatic resolution and 8-m multi-spectral resolution. Courtesy of NASA Earth Observatory, with image provided by Cheng-Chien Liu, National Cheng-Kung University, and An-Ming Wu, NSPO, Taiwan.

Information Contacts: NASA Earth Observatory (URL: http://earthobservatory.nasa.gov/); Ralph Harrington, The Volcanism Blog (URL: http://volcanism.wordpress.com); Matthew R. Patrick, Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA; Simon Carn, Department of Geological and Mining Engineering and Sciences, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931, USA (URL: https://so2.gsfc.nasa.gov/); Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/).

Weekly Reports - Index


2008: November


19 November-25 November 2008 Citation IconCite this Report

During 19-24 November, the MODIS satellite continued to detect thermal anomalies over the area near Dalaffilla and Alu volcanoes from the eruption that began on 3 November.

Source: Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts Team


12 November-18 November 2008 Citation IconCite this Report

Night-time satellite imagery from 8 November of the eruption that began on 3 November near Dalaffilla and Alu volcanoes revealed a multi-lobed lava-flow field with a primary channelized flow that traveled NE. The source appears to be a one or more NW-SE-trending eruptive fissures NW of Dalaffilla. The flow field on the 8 November image was an estimated 9.3 km long and 3 km wide, with an area of about 15 square kilometers. Thermal anomalies detected by satellites were present during 12-16 November.

Sources: Simon Carn; Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts Team; US Geological Survey Hawaiian Volcano Observatory (HVO)


5 November-11 November 2008 Citation IconCite this Report

An eruption of a volcano NW of Erta Ale in Ethiopia's Afar region began on 3 November. Satellite imagery showed a large sulfur dioxide cloud that drifted E over the Arabian Peninsula. According to news articles, observers reported ground shaking, hearing loud noises and explosions from a distance, and seeing smoke. Widespread lava flows were also noted. Extensive thermal anomalies near Dalafilla and Alu volcanoes were detected, consistent with lava effusion, although the source of the lava flows was not known. Thermal anomalies continued to be detected during 3-11 November.

Sources: Bloomberg; Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts Team; OMI Sulfur Dioxide Group


Bulletin Reports - Index

Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

10/2008 (BGVN 33:10) Satellite data reveals rift axis lavas erupted in November 2008

12/2008 (BGVN 33:12) Lava flow-field size unchanged for months; thermal alerts ceased 28 December




Information is preliminary and subject to change. All times are local (unless otherwise noted)


October 2008 (BGVN 33:10) Citation IconCite this Report

Satellite data reveals rift axis lavas erupted in November 2008

During November 2008, lava extruded from fissures and by 8 November covered a heavily faulted zone spreading over about 15 km2 in the Afar (or Danakil) depression. This eruption is ~ 25 km NW of Erta Ale volcano, in the Erta Ale volcanic range (figure 1). The range lies along the axis of the the NW-trending Danakil depression, a hot, arid, and desolate rift basin with a floor in places ~ 100 m below sea level. Going NW along the rift from Erta Ale, the named volcanic centers include Bora Le Ale, Dalaffilla, Alu, and Gada Ale. The tectonically active area (figure 2) has extremely low population density and scientists' field reports have yet to emerge. Prior to this event, there were five eruptive episodes in the region since 1967, three of those since September 2005 (table 1).

Figure (see Caption) Figure 1. Sketch map of the Afar triangle region with highly simplified tectonics and some of the region's volcanoes indicated as triangles. The Afar region (shaded) contains the Afar (rift-rift-rift) triple junction. Continental rifting takes place along the East African rift (EAR), with the Nubian plate on the W, and the Somalian plate on the E. The Arabian plate resides on the N. Note Erta Ale volcano in the N Afar (along the Danakil depression). The volcano Jebel et Tair (location approximate) is indicated with "JT." Revised from a map prepared by the USGS.
Figure (see Caption) Figure 2. A schematic map of the Afar indicating key volcanic and tectonic features including the Erta Ale volcanic range and Jebel at Tair volcano in the Red Sea. Key patterns: 1) Outcropping continental basement, 2) Continental rift material, and 3) Oceanic crust formed during the last 3-4 million years. Modified from Barberi and Varet (1975).

Table 1. A synopsis of known Afar region eruptions since 1967, including the case at hand, Dalaffilla. Compiled from Smithsonian volcano reports (CSLP and SEAN are Smithsonian BGVN predecessors).

Volcano (Country) Location (with respect to Erta Ale) Eruption dates Comment
Erta Ale (Ethiopia) -- 1967-present Active lava lake(s) ongoing through present [eg. CSLP 22-71, BGVN 33:06].
Ardoukôba (Djbouti) 300 km SE 07-14 Nov 1978 Ardoukôba (Asal rift) produced small cinder cone and lava flows on rift floor [SEAN 03:11, 03:12].
Dabbahu (Ethiopia) 113 km SE Sep 2005 Short-lived explosive eruption with apparent dome in the deep portion of the elongate crater (Also see Wright and others, 2006) [BGVN 30:09].
Manda Hararo (Ethiopia) 160 km S 12 Aug-Sep 2007 Lava flows, numerous small spatter and scoria cones; occasional flames. Recent fault movement. Located in the Karbahi graben between the settlements of Semera and Teru [BGVN 32:07].
Jebel at Tair (Yemen) 250 km NNE 30 Sep 2007-01 Jan 2008 An explosive and effusive eruption of lava on inhabited island in the S-central Red Sea (evacuation and fatalities) [BGVN 32:10, 32:04].
Dalaffilla (Ethiopia) 25 km NW 03 Nov 2008 This is the first BGVN report on either Dalaffilla or adjacent Alu volcanoes (mainly satellite data available thus far in late November 2008).

The conical summit of Dalafilla (which means "cut neck" in the Afar language) lies about 6 km SE of the center of the elongated summit horst of Alu (figure 3). The current eruption took place from vents between these two rift-axis centers, both of which have extensive vents, fissures, and faults trending along the rift axis. Determination of the provenance of flank vents can be problematical in a rift setting such as this that displays adjacent, but slightly offset elongated, rift-parallel volcanism. Preliminary analysis of satellite imagery suggests that the lava flows originated from fissures or vents extending downslope from the sides of the Dalafilla volcanic center.

Figure (see Caption) Figure 3. Geological map (1972) of a portion of the Erta Ale Volcanic Range (Danakil Depression ? Ethopia) showing the relative locations of volcanoes Alu, Dalaffilla, and Bora Le Ale. The new deposits are most extensive in an area E to SE of Alu, along the axial trend that corresponds with Dalaffilla. N is to the top; the original map was at a scale of 1 to approximately 100,000. In the colored version of this map, orange and brighter purple colors represent silicic rocks and darker purple and blue colors represent basaltic rocks. From Barbari and Varet (1972).

Thermal radiance remained significant into at least early December. Available news reports claimed the area of new lavas as 20-fold larger than they turned out to be, casting doubt on their other descriptions of the eruption. Still, the plume reached 13-16 km altitude and delivered ~ 10,000-20,000 metric tons of SO2 into the atmosphere.

Geolocation errors. During the early phases of this eruption, while attempting to determine the source volcano, it became apparent that the GVP coordinates for Alu were displaced towards the E in the area with the new flows. Inaccurate volcano locations can result from older, imprecise, base maps, especially in remote areas. They may also be caused by the lack of a global datum, even when precise maps are available. More recent satellite imagery and mapping techniques are gradually improving the situation, and the location for Alu has been corrected (see figure 7 below).

Eruptive activity. Charles Holliday found Meteosat-9 infrared (IR) satellite data to constrain the eruption's start on 3 November 2008. He went on to estimate the plume's maximum height, which first occurred about one hour after any cloud was first visible. He had images every 15 minutes and found no sign of an eruption cloud as late as 1245 UTC (0945 local time). This was followed by a small initial cloud appearing at 1300 UTC, which then grew to larger clouds blowing E. Looking at the Meteosat-7 IR data, Holliday found the eruption at around 1350 UTC.

Holliday determined the sequence of coldest pixels (table 2). He found the coldest pixel of the set in an image representing Meteosat-9 at 1350 UTC, about -73°C, and by comparing an atmospheric sounding made over Abha, Saudi Arabia inferred a maximum plume height of 15.7 km. The coldest pixel, -64°C, was in a Meteosat-7 IR image from 1350 UTC. Comparison with the same OEAB sounding as above obtained a maximum plume height 13.5 km.

Table 2. Times and coldest pixels related to the Dalaffilla eruption seen in Meteosat-9 IR satellite data on 3 November 2008. The last two rows include ancillary data and results used to describe the coldest pixels on the Meteosat-9 and -7 IR data. The data were used to estimate the maximum cloud height (reached around 1400 UTC). The Meteosat-7 IR data for other times was not available but the one entry (at 1350 UTC) was described as the coldest. Courtesy of Charles Holliday.

Time (UTC) on 3 Nov Coldest pixel from IR image Meteosat-9 (Meteosat-7)
1300 -66°C (?)
1315 -73°C (?)
1330 -71°C (?)
1345 -71°C (@1350 UTC, -64°C)
1400 -73°C (?)
1415 -73°C (?)
1430 -71°C (?)
Atmospheric sounding at 1200 UTC from Rawinsonde station at Abha, Saudi Arabia, WMO 41112, OEAB; located ~545 km NNE (at 18.24°N, 42.66°E). Equatorial subpoints (IR resolution): Meteosat-7, 57.5°E (5 km); Meteosat-9, 0° (3 km).
Conclusion (Plume top estimates): Meteosat-9, 15.7 km altitude at 1315 UTC
  Meteosat-7, 13.5 km altitude at 1350 UTC

Activity could also be identified in a MODIS (Moderate-resolution Imaging Spectro-radiometer) image from 4 November (figure 4), a composite using three of 36 available bands, from orange-red and into the IR (bands 7-2-1). Although the areas of high thermal flux may lack detail on this 250-m resolution image, that area lacks the SW-directed spur seen on some later photos.

Figure (see Caption) Figure 4. The Dalaffilla eruption as it appeared on a MODIS image for 0730 UTC on 4 November 2008. By this time the lava had spread considerably NW but the spur of lava seen later to the SW was not in evidence on this image with pixel size of 250 m. The image compiled bands 7, 2, and 1. Courtesy of NASA.

In a 6 November message Simon Carn noted that in terms of sulfur dioxide (SO2), the November eruption generated a large cloud. As detected by the Ozone Monitoring Instrument (OMI) and the Atmospheric Infrared Sounder (AIRS), the cloud initially drifted E over the Arabian peninsula. The cloud was clearly linked to the eruption because MODIS/MODVOLC data from the Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System confirmed an extensive hotspot.

A total of 0.1-0.2 Tg (tetragram) of SO2 (1 Tg = 1012 g = 109 kg = 106 Tons) was measured in the eruption cloud by OMI at ~ 1100 UTC on 4 November, by which time the SO2 cloud had reached S Iran. The cloud had dissipated and moved east by the next day (figure 5). On 6 November, the plume appeared the same or even stronger than the one the previous day. But on subsequent days the plumes became much smaller.

Figure (see Caption) Figure 5. OMI snapshots of the Dalafilla SO2 plume stretching NE on 4-5 November 2008. During 1050-1054 UTC on 4 November there was a very dense, broad, and unbroken plume truncated at the image's N margin. For 5 November during 0956-1137 UTC, an often more diffuse and segmented plume with greatest density near the Yemen-Saudi Arabian border. The 2° N-S increments scribed on the margins represent 222 km.Courtesy of Simon Carn and the OMI website.

NASA's Earth Observatory first discussed this phase of the eruption with reference to a MODIS image captured on 4 November. Owing to an extensive white plume, the analysts could not make out the lava field, but they saw widespread haze towards the N (figure 6) that they and NOAA analysts interpreted as vog (volcanic smog, which results from volcanic gases such as SO2 mixing with water vapor and oxygen in the presence of sunlight).

Figure (see Caption) Figure 6. A MODIS image from showing widespread haze to the N of the Dalaffilla eruption site at 0735 UTC on 4 November. At this early phase of the eruption analysts incorrectly attributed the eruption to Erta Ale. Courtesy of NOAA/NASA.

Matthew Patrick of the USGS processed and provided a nighttime ASTER image, taken 8 November 2008 at 1942 UTC, showing the lava flow between Dalaffilla and Alu volcanoes, and Simon Carn superimposed it on Google Earth imagery (figure 7). Carn noted that the underlying pre-eruption Google Earth imagery shows relatively youthful cinder cones and lava flows in this region.

Figure (see Caption) Figure 7. The pattern of high thermal flux in the Dalaffilla area superimposed on a Google Earth map with the corrected placemark locations. Courtesy of Matt Patrick and Simon Carn.

Patrick made these preliminary assessments based on 90-m resolution thermal infrared (TIR) data from 8 November, and on later visible data. The registration between these data sets was imperfect in the E-W direction. The lava flow comprised a multi-lobed field from a fissure or fissure system. Flow direction was transverse to the rift axis, to the NE. The flow field on 8 November was 9.3 km long by ~ 3.0 km wide, and its surface area was 14.9 km2. The flows originated from NW-trending fissures extending over a distance of 2.7 km.

Patrick later noted that the main channel originated along a fissure that cut the surface near a prominent older cinder cone. The cone was visible in the pre-eruption Google Earth imagery. The geologic map by Barberi and Varet (1970), shows similar NW-SE-trending eruptive fissures of likely Holocene age (cutting the youngest basalts) in this same area between Dalafilla and Alu (figure 3).

A second Earth Observatory report featured one ASTER image made before the eruption, and another several weeks after on 16 November (figure 8). That figure presents one of the better images for inspecting the upper lava flow field (which appears dark in the image).

Figure (see Caption) Figure 8. Dalaffilla (bottom center) and Alu (ellipse, left center) volcanoes and the new lava flow field that flowed downslope to the NE. Courtesy of NASA Earth Observatory.

MODVOLC Thermal Alerts. In harmony with the IR data above, satellite thermal alerts (anomalies) measured by the Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System swelled. For years before 3 November 2008 they stood at zero. On 3 November they rose to 148 pixels. On passes the next day the number of thermal-alert pixels had dropped and continued to descend (at 0735 UTC, 31 anomalies; at 1040 UTC, 18 anomalies). Thereafter through at least early December, many days had 1 to 10 thermal alert pixels. On occasional days, particularly during 5-17 November, as many as 26 appeared. As of early December, the anomalies were still around several pixels. Spatially, these anomalies typically overlay and extended beyond the flow field.

References. Barberi, F., and Varet, J., 1970, The Erta Ale volcanic range (Danakill depression, Northern Afar, Ethiopia): Bull Volc., v. 34, p. 848-917.

Barberi, F., and Varet, J., 1972, Geological map of the Erta Ale volcanic range (Danakil depression, Northern Afar, Ethiopia): Centre National de la Recherche Scientifique (France) and Consiglio Nazionale delle Ricerche (Italy), approximate scale, 1:100,000, includes explanatory text, ISBN 2-222-01521-9.

Barberi, F., and Varet, J., 1975, Volcanological research in Afar (L.R. Wager Prize Lecture): Bull. Volc., v. 39, no. 2, p. 5-13.

Wright, T.J., Ebinger, C., Biggs, J., Ayele A., Yirgu, G., Keir, D., and Stork, A., 2006, Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode: Nature, v. 442, p. 291-294 (20 July 2006), doi:10.1038/nature04978.

Wood, J., and Guth, A., 2008, East Africa's Great Rift Valley: a complex rift system: Geology.com (URL: http://geology.com/articles/east-africa-rift.shtml)

Information Contacts: Jacques Varet, Geoscience for a Sustainable Earth, BRGM 3, avenue Claude-Guillemin, 45060 Orléans cedex 02, France; Charles Holliday, U.S. Air Force Weather Agency (AFWA)/XOGM, Offutt Air Force Base, NE 68113, USA; Matthew R. Patrick, Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Simon Carn, Dept of Geological and Mining Engineering and Sciences, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931, USA (URL: https://so2.gsfc.nasa.gov/); Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/); Gezahegn Yirgu, Dept of Earth Sciences, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia; NASA Earth Observatory (URL: http://earthobservatory.nasa.gov/).


December 2008 (BGVN 33:12) Citation IconCite this Report

Lava flow-field size unchanged for months; thermal alerts ceased 28 December

The eruption that began on 3 November 2008 (BGVN 33:10) significantly slowed or ceased prior to January 2009. The region is the scene of sporadic fighting, thwarting direct reports from people in the field, and forcing greater reliance on remote-sensing imagery.

Looking at Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite system images for 19 December 2008 and 4 January 2009 (figure 9), Matt Patrick found little significant change in the shape or area of the lava flow field since 8 November 2008 (see image in BGVN 33:10).

Figure (see Caption) Figure 9. Satellite ASTER images over Dalaffilla and Alu volcanoes on 19 December 2008 and 4 January 2009. Shown are nighttime thermal images (band 14, 11-micron wavelength) showing flow to the NE from a fissure or fissure system between the volcanoes. Courtesy of Matt Patrick.

Thermal alerts over the eruption site reported by the MODVOLC system were absent after 28 December 2008 (figure 10) through at least early February 2009. At the start of the eruption (identified on 3 November at 1920 UTC) there were 148 alerts in a circular pattern well extending outboard but engulfing the densest area of alerts over the main lava field. Following the initial eruption, the alert pixels concentrated primarily on the lava flow. No thermal anomalies were detected for at least several years before the November eruption.

Figure (see Caption) Figure 10. A plot of the maximum number of daily MODVOLC thermal alerts at Dalaffilla during November-December 2008. Courtesy of the Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System.

NASA's Earth Observatory (EO) released a true-color image captured by Taiwan's Formosat-2 satellite (figure 11). The image caption, by Ralph Harrington, noted that fresh flows from the recent eruption appear darker than the older weathered flows. Lava spread from the fissure several kilometers to the NE, as well as S and SW. The image also appears to show spatter cones associated with the fissures.

Figure (see Caption) Figure 11. A Formosat-2 satellite true-color image (enhanced here) acquired 25 December 2008 of the Alu and Dalaffilla portion of the Erta Ale range of the Afar region. FORMOSAT-2, developed by the National Space Organization (NSPO), launched in 2004 with 2-m panchromatic resolution and 8-m multi-spectral resolution. Courtesy of NASA Earth Observatory, with image provided by Cheng-Chien Liu, National Cheng-Kung University, and An-Ming Wu, NSPO, Taiwan.

Information Contacts: NASA Earth Observatory (URL: http://earthobservatory.nasa.gov/); Ralph Harrington, The Volcanism Blog (URL: http://volcanism.wordpress.com); Matthew R. Patrick, Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA; Simon Carn, Department of Geological and Mining Engineering and Sciences, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931, USA (URL: https://so2.gsfc.nasa.gov/); Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/).

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Eruptive History

There is data available for 1 confirmed Holocene eruptive periods.

2008 Nov 3 - 2008 Dec 16 (?) ± 15 days Confirmed Eruption VEI: 3 (?)

Episode 1 | Eruption W and NW of Dalaffilla
2008 Nov 3 - 2008 Dec 16 (?) ± 15 days Evidence from Observations: Reported

List of 4 Events for Episode 1 at W and NW of Dalaffilla

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Eruption cloud
   - - - -    - - - - Lava flow
2008 Nov 3    - - - - VEI (Explosivity Index)
Deformation History

There is data available for 3 deformation periods. Expand each entry for additional details.


Deformation during 2008 Nov 19 - 2010 [Uplift; Observed by InSAR]

Start Date: 2008 Nov 19 Stop Date: 2010 Direction: Uplift Method: InSAR
Magnitude: Unknown Spatial Extent: 10.00 km Latitude: 14.000 Longitude: 41.000

Remarks: Post-eruptive uplift in same pattern as co-eruptive subsidence. Uplift began on 5 November 2008 for the northern portion, and on 19 November 2008 for the southern portion

Figure (see Caption)

Time-evolving cumulative volume changes. a,b, Pre-eruptive and c,d, post-eruptive periods. Circles represent acquisitions colour-coded to satellite track number, orbit and mode (for example A-I2, ascending orbit in mode 2). The red dashed line in a represents the best-fit curve using all the data, whereas the black dashed line is the best-fit curve excluding the last two circles. The lines highlight the different deformation patterns, uplift July?September 2008 but quiescence a month before the eruption. Selected interferograms and their models are shown for given time intervals on the sides. The colour bar shown in the upper left corner applies to all interferograms.

From: Pagli et al. 2012.


Reference List: Pagli et al. 2012.

Full References:

Pagli, C., T. J. Wright, C. J. Ebinger, S.H. Yun, J. R. Cann, T. Barnie, and A. Ayele,, 2012. Shallow axial magma chamber at the slow spreading Erta Ale Ridge. Nature Geoscience, 5: 284-288.

Deformation during 2008 Nov - 2008 Nov [Subsidence; Observed by InSAR]

Start Date: 2008 Nov Stop Date: 2008 Nov Direction: Subsidence Method: InSAR
Magnitude: 190.000 cm Spatial Extent: 10.00 km Latitude: 14.000 Longitude: 41.000

Remarks: Co-eruptive subsidence modeled by a dike, sill, and Mogi source

Figure (see Caption)

ALOS ascending co-eruptive interferogram

From: Pagli et al. 2012.


Reference List: Pagli et al. 2012.

Full References:

Pagli, C., T. J. Wright, C. J. Ebinger, S.H. Yun, J. R. Cann, T. Barnie, and A. Ayele,, 2012. Shallow axial magma chamber at the slow spreading Erta Ale Ridge. Nature Geoscience, 5: 284-288.

Deformation during 2008 Jul - 2008 Sep [Uplift; Observed by InSAR]

Start Date: 2008 Jul Stop Date: 2008 Sep Direction: Uplift Method: InSAR
Magnitude: 9.000 cm Spatial Extent: 3.00 km Latitude: 14.000 Longitude: 41.000

Remarks: Pre-eruptive deformation prior to November 2008 Alu-Dalafilla eruption

Figure (see Caption)

Time-evolving cumulative volume changes. a,b, Pre-eruptive and c,d, post-eruptive periods. Circles represent acquisitions colour-coded to satellite track number, orbit and mode (for example A-I2, ascending orbit in mode 2). The red dashed line in a represents the best-fit curve using all the data, whereas the black dashed line is the best-fit curve excluding the last two circles. The lines highlight the different deformation patterns, uplift July?September 2008 but quiescence a month before the eruption. Selected interferograms and their models are shown for given time intervals on the sides. The colour bar shown in the upper left corner applies to all interferograms.

From: Pagli et al. 2012.


Reference List: Pagli et al. 2012.

Full References:

Pagli, C., T. J. Wright, C. J. Ebinger, S.H. Yun, J. R. Cann, T. Barnie, and A. Ayele,, 2012. Shallow axial magma chamber at the slow spreading Erta Ale Ridge. Nature Geoscience, 5: 284-288.

Emission History

There is data available for 1 emission periods. Expand each entry for additional details.


Emissions during 2008 Nov 03 - 2008 Nov 03 [150 kt SO2 at 16 km altitude]

Start Date: 2008 Nov 03 Stop Date: 2008 Nov 03 Method: Satellite (Aura OMI)
SO2 Altitude Min: 16 km SO2 Altitude Max: 16 km Total SO2 Mass: 150 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
20081103 16.0 150.000
Photo Gallery

The steep-sided, conical Dalafilla volcano rises 300 m above surrounding lava fields of Alu volcano in the foreground in this view from the NW. This morphology, unusual for the Erta Ale Range volcanoes, results from the extrusion of viscous, silicic lava flows. These silicic flows extend primarily to the east from the 613-m-high summit. On the western side they are blocked by walls of a horst structure along the crest of the Erta Ale Range that forms the linear ridge in the right side of the photo.

Copyrighted photo by Marco Fulle, 2002 (Stromboli On-Line, http://stromboli.net).
The summit region of Alu volcano is located left of the center of this Landsat image, south of Lake Bakili (top center). Alu lies SE of Gada Ale volcano (upper left), which rises above the western shore of the lake, and NW of Dalafilla volcano (bottom center). Fissure vents west of the horst have fed silicic lava flows, and other fissures to the south have produced voluminous basaltic lava flows that extend north as far as Lake Bakili.

NASA Landsat image, 1999 (courtesy of Hawaii Synergy Project, Univ. of Hawaii Institute of Geophysics & Planetology).
The summit region of Alu volcano is primarily composed of older basaltic lava flows. Major fumarolic activity is located on the numerous parallel faults, some of which have scarps up to 100 m high. Fissure vents west of the horst have fed silicic lava flows, and other fissures to the south have produced voluminous basaltic lava flows that extend north as far as Lake Bakili.

Photo by Richard Roscoe, 2002.
This nighttime ASTER image, taken on 8 November 2008 at 1942 UTC shows in white the lava flows between Dalafilla and Alu volcanoes superimposed on Google Earth imagery. The first historical eruption began on 3 November 2008 from one or more fissures located W and NW, between Dalafilla and Alu volcanoes. An initial sulfur-rich eruption plume was followed by extensive lava flows to the NE. MODIS thermal alerts were detected until 28 December.

NASA ASTER image, 2008 (courtesy of Matthew Patrick, USGS, and Simon Carn (Michigan Tech University).
GVP Map Holdings

Maps are not currently available due to technical issues.

Smithsonian Sample Collections Database

There are no samples for Alu-Dalafilla in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites