According to NASA's Earth Observatory, satellite images of Nabro acquired on 28 September showed heat from the vent in the central crater, and from an area 1.3 km S of the vent that indicated an active lava flow. A small and diffuse plume rose from the vent. A region of seemingly thicker black ash (that completely covered the sparse vegetation) was noted S of the crater and thinner layers of ash (with some areas of visible vegetation) flanked either side of the region.

All times are local (= UTC - 9 hours [or 8 hours early April-late October])

2011: June | July | September |

---

28 September 2011            Back to Top

According to NASA's Earth Observatory, satellite images of Nabro acquired on 28 September showed heat from the vent in the central crater, and from an area 1.3 km S of the vent that indicated an active lava flow. A small and diffuse plume rose from the vent. A region of seemingly thicker black ash (that completely covered the sparse vegetation) was noted S of the crater and thinner layers of ash (with some areas of visible vegetation) flanked either side of the region.

Sources: NASA Earth Observatory

---

13 July 2011            Back to Top

Based on analyses of satellite imagery, the Toulouse VAAC reported that on 16 July an ash plume from Nabro rose to altitudes below 5.5 km (18,000 ft) a.s.l. A weak eruption detected on 17 July decreased through the day then appeared to have stopped.

Sources: Toulouse Volcanic Ash Advisory Centre (VAAC)

---

29 June 2011            Back to Top

A satellite image of Nabro acquired on 29 June showed a clear view of the caldera and the vent within the active crater near the middle of the caldera. Lava flows to the W, and within the crater (E and S of the vent), continued to be hot. A brown ash plume rose from the vent and drifted S.

Sources: NASA Earth Observatory

---

22 June 2011            Back to Top

A satellite image of Nabro acquired on 22 June showed a gas-and-ash plume rising from the caldera and drifting W. According to a news article, the eruption resulted in at least seven deaths, injured many, and displaced thousands in Eritrea, and affected about 5,000 Ethiopians living near the border. Two satellite images acquired on 24 June show the erupting vent, plumes and emissions, and lava flows in detail. One false-color image highlighted hot areas throughout the lava flow and flow front, as well as hot material above the vent. Gas emissions rising from the lava flow were also detected. A natural-color image showed fresh but cooled lava flows in the N part of the caldera. A dark ash plume rose from the vent, and at higher altitudes a plume composed of water vapor and sulfur dioxide drifted W and obscured the active lava flow. Black ash deposits covered the landscape to the S and W. During 22-26 June large amounts of sulfur dioxide in the region continued to be detected by satellite images. Based on analyses of satellite imagery, the Toulouse VAAC reported that during 26-27 June plumes rose to altitudes up to 6.1 km (20,000 ft) a.s.l.

Sources: NASA Earth Observatory , Toulouse Volcanic Ash Advisory Centre (VAAC) , NASA Global Sulfur Dioxide Monitoring , Sudan Tribune

---

15 June 2011            Back to Top

An eruption from Nabro that started on 12 June continued to produce a plume. Based on analyses of satellite imagery, the Toulouse VAAC reported that during 15-20 June plumes comprised mostly of water and sulfur dioxide rose to altitudes of 6.1-7.9 km (20,000-26,000 ft) a.s.l. Ash was occasionally detected near the volcano. Satellite imagery posted on MODIS Web showed a dark brown ash plume fanning out to the SW on 19 June. A thermal satellite image acquired at night on 19 June revealed a 15-km-long lava flow that had traveled NW. A high-altitude plume, likely rich in water vapor, rose from the erupting vents and a diffuse ash-rich plume drifted SW.

News articles stated that ash had covered a well-known mine that produces edible salt, and had contaminated food and water sources. During 15-16 June several airlines cancelled some domestic and international flights, including in and out of Addis Abeba (Ethiopia), neighboring Djibouti, and Khartoum (Sudan).

Sources: NASA Earth Observatory , Toulouse Volcanic Ash Advisory Centre (VAAC) , Addis Fortune , Bloomberg , NASA MODIS Rapid Response System

---

8 June 2011            Back to Top

According to the USGS Earthquake Hazards Program, an earthquake swarm was detected during the evening of 12 June on the border of Ethiopia and Eritrea, in the vicinity of Nabro, the most prominent of three volcanoes with large summit calderas aligned in a NE-SW direction SW of Dubbi volcano. The swarm began at 1837 with an M 5.1 earthquake. Several more were detected between M 4.3 and 5.1 over the next few hours. Two M 5.7 earthquakes at depths of 10.1 km and 9.9 km were detected at 2332 on 12 June and 0003 on 13 June, respectively.

The Toulouse VAAC reported that an eruption from Nabro (originally attributed to Dubbi) started between 0000 and 0200 on 13 June. An eruption plume initially rose to altitudes of 9.1-13.7 km (30,000-45,000 ft) a.s.l. then was later detected at altitudes of 6.1-10.7 km (20,000-35,000 ft) a.s.l. during 13-14 June. According to the Eritrean Ministry of Information, ashfall covered hundreds of kilometers and the government evacuated area residents. Witnesses noted that the eruption had started at about 2100 on 13 June. Satellite images that same day showed the plume drifting more than 1,000 km NW, over parts of Sudan. On 14 June a detached ash cloud was detected over southern Israel according to news articles. A plume from Nabro was not obvious on satellite imagery.

Sources: Toulouse Volcanic Ash Advisory Centre (VAAC) , US Geological Survey Earthquake Hazards Program , NASA MODIS Rapid Response System , Eritrean Ministry of Information , The Jerusalem Post

---

Below is a summary of eruption dates and Volcanic Explosivity Indices (VEI).

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title. Additional discussion of data sources can be found under Volcano Data Criteria.

CNR-CNRS, 1975. {Geological Maps of Afar: 1, Northern Afar (1971); 2, Central and Southern Afar} (1975). La Celle St Cloud, France: Geotechnip

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. {IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior}.

Katsui Y (ed), 1971. List of the World Active Volcanoes. {Volc Soc Japan draft ms}, (limited circulation), 160 p

Wiart P, Oppenheimer C, 2005. Large magnitude silicic volcanism in north Afar: the Nabro volcanic range and Ma'alalta volcano. {Bull Volc}, 67: 99-115

Wood C A, 1980. . (pers. comm.)

The 2218-m-high Nabro stratovolcano is the highest volcano in the Danakil depression of northern Ethiopia and Eritrea. Located at the SE end of the Danakil Alps, Nabro lies in the Danakil horst. Nabro is the most prominent and NE-most of three volcanoes with large summit calderas aligned in a NE-SW direction SW of Dubbi volcano. These three volcanoes, along with Sork Ale volcano, collectively comprise the Bidu volcanic complex. The complex Nabro stratovolcano is truncated by nested calderas, 8 and 5 km in diameter. The larger caldera is widely breached to the SW. Nabro was constructed primarily of trachytic lava flows and pyroclastics. Post-caldera rhyolitic obsidian domes and basaltic lava flows were erupted inside the caldera and on its flanks. Some very recent lava flows were erupted from NNW-trending fissures transverse to the trend of the Nabro volcanic range.