Emergency response to the 2011 eruption of the Nabro volcano

The Nabro Volcano in the sparsely populated Southern Red Sea region of Eritrea unexpectedly erupted for the first time on record on June 12, 2011, with very little warning, and bearing significant societal and environmental consequences during several days of eruption. Most of the impacts of the volcano fell on the Eritrean village of Siroru. At the same time, strong seismic activities occurred on the other side of the border in Ethiopia, at the Mallahle volcano area. The eruption produced a large ash plume that drifted westwards over northern Africa and quickly reached more than 1000 km length. The situation triggered an exemplary response which involved several international actors:

I. At monitoring level

- At time of eruption, there were no seismic or other monitoring networks operating in Eritrea. Seismometers in Ethiopia, Yemen and Djibouti did record seismicity associated with the volcano, but they did not provide information of operational value at the time of the eruption. However, earthquakes occurring over several hours before the eruption, did prompt a rapid evacuation of settlements, notably those within Nabro’s caldera.

- Data in relation to Nabro and surroundings were obtained from ten stations in Ethiopia, eight in Djibouti and one in Yemen. No major earthquake was reported by international or regional centers (United States Geological Survey (USGS) or ISC) prior to the eruption, with the exception of a 4.5-MW event on 31 March 2011 (i.e. just over 10 weeks before the eruption). Seismicity occurred beneath both Nabro and Mallahle volcanoes.

II. At emergency response level

- The evacuation prompted by the earthquakes prior to the eruption saved many lives

- An earthquake detected on 31 March 2011 has served to sensitize and increase preparedness of the population in advance of the eruption. A visiting scientific team in May 2011 briefed village and district administrators and community leaders on what to do in the event of future earthquakes, namely to vacate their homes and avoid structures that could collapse and areas susceptible to landslides.

- Village and district administrators in Eritrea are mostly war veterans well-versed in aspects of emergency management and in coping with situations with limited means at their disposal. Their experience was decisive in the immediate local management of the unfolding emergency on 12 June 2011. An army detachment based close to the local administration building in Siroru maintained radio contact with the Southern Red Sea Region Administration (SRSRA) in the regional capital, Assab (about 120 km away, as the crow flies). Together with other nearby units, they helped to evacuate people as the crisis developed on the night of 12/13 June 2011.

- The SRSRA committee tasked with coordinating the response to the unfolding humanitarian crisis dispatched a medical team and provision of emergency relief. Other government agencies provided longer term assistance to displaced people in respect of health care and schooling.

- In total, about 11,780 people were evacuated. Seven people were killed and three were injured during the eruption. Many of the people displaced by the eruption were unable to return to their homelands; substantial numbers have been permanently resettled elsewhere.

- The losses in household goods were substantial. In previously settled areas of the caldera floor south of the vent region, tephra accumulated to depths of several metres, burying or partially burying many structures. Two villages were completely destroyed, and recorded losses include 19,839 goats and sheep, 460 cattle, 834 camels and 142 donkeys. Total economic losses were estimated to be in the region of US$3 million.

- On the Ethiopian side of the border, the caldera of Mallahle volcano was inhabited and received significant fallout of tephra from the eruption plumes. Affected communities are said to have received assistance in Eritrea despite the tension between the two countries.

- In terms of civil aviation issues, the region falls under the responsibility of the Toulouse Volcanic Ash Advisory Centre. The volcanic clouds resulted in disruptions to aviation in the region with international flights in East Africa and the Middle East particularly affected.

III. Conclusion

Considering that more than 3,000 people lived within the Nabro caldera itself, the seven fatalities toll is remarkably low. This reflects a rapid, largely spontaneous evacuation of settlements close to the vent region, prompted by premonitory ground shaking and the first signs of eruption.

The study of the Nabro eruption has highlighted the importance of diverse Earth observation techniques for monitoring volcanoes in comparatively remote regions, especially where local ground-based sensor networks are limited or lacking.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4562108/

GFMD 2016 RT 3.1 "Migrants in Situations of Crises"

National Government of Eritrea; United States Geological Survey (USGS) and others