Rift volcanism: past, present and future

Lead Research Organisation: University of Southampton
Department Name: Sch of Ocean and Earth Science

Abstract

Early explorers called it Africa's Great Rift Valley, a narrow strip that runs for thousands of kilometres from Djibouti to Mozambique and is perhaps most famous for the vast herds of the Serengeti, mountain gorillas and dramatic landscapes of high peaks and fertile plains. The mountains and valleys are the signs of a continent slowly tearing apart. Moving apart more slowly than your finger nails grow, the African continent will one day split into two, creating a new ocean. As the Earth's crust stretches and thins - like plasticine when you pull it - rocks melt, and the resulting magma rises to the surface. The resultant eruptions have had a dramatic and varied impact on the landscape: great lakes have filled the holes left by enormous eruptions; eruptions of volcanic glass have created a chain of peaks, and wide fields are filled with scattered cones and lava flows. This volcanic landscape is hazardous - a recent report for the World Bank ranked 49 of Ethiopia's 65 volcanoes in the highest category of hazard uncertainty. The high temperatures associated with magma in the Rift Valley make it a rich source of carbon-neutral geothermal power. Multi-billion dollar investments by development agencies are driving a ten-fold expansion in the geothermal infrastructure in East Africa over the next decade.
However, the majority of scientific research has focussed on volcanoes in other tectonic settings, such as Hawaii and Japan, leaving the volcanoes of the East African Rift largely a mystery. For many of them, we can't even say when the last eruption look place and there is no monitoring equipment to detect the early stages of an upcoming eruption. The eruption of Nabro volcano in 2011 was a timely reminder of the potential threats. Situated on the frontier between Ethiopia and Eritrea, the area is remote and sparsely populated, yet the eruption caused 32 fatalities, displaced >5000 people and disrupted regional aviation. Had this eruption originated from one of other 29 volcanoes with the same perceived hazard, but in densely-populated central Ethiopia, the humanitarian and societal cost would have been considerable.
RiftVolc will focus on the volcanoes of the Main Ethiopian Rift in central Ethiopia. The aim is to understand their past behaviour, look for subtle signs of present-day activity and assess the threat posed to the infrastructure and people on and around them. RiftVolc will involve scientists from many disciplines working together to produce an integrated view of the past, present and future of the volcanoes in this region and compare it to other parts of East Africa and volcanoes elsewhere. Together we will spend several months out in Ethiopia, collecting samples, mapping the geology and deploying geophysical instruments, before returning to the lab to use analyse the data and create computer models of the results. Petrologists and geochemists will look at the lavas and ash to figure out the timing, size and style of past eruptions. Geophysicists will look for tiny earthquakes, changes in gravity, the passage of electrical currents and movements of the Earth's surface to understand the plumbing system feeding the volcanoes today. Finally, experts in hazard assessment will model possible scenarios and create a long-range eruption forecast for Ethiopia. We will work with our colleagues in the University of Addis Ababa and the Geological Survey of Ethiopia to ensure our findings are appropriate communicated to the government, industry and people of Ethiopia and with international groups such as the Global Volcano Model to communicate our results to development agencies such as the UN and the World Bank.

Planned Impact

Beneficiaries
National Government (Devolved Government & Government Agencies)
- The Institute of Geophysics, Space Science and Astronomy (IGSSA) at Addis Ababa University is the national organisation providing geophysical monitoring data and advice during unrest and eruptions, and the School of Earth Sciences advises on the character of past eruptions. There are no trained volcanologists in Ethiopia so they collectively provide scientific advice to the Ministry of Agriculture's Disaster Risk Management and Food Security Sector (DRMFSS), the Civil Aviation Authority and Ethiopian Pilots Association during an eruption.
- The Geological Survey of Ethiopia's geoscience data, advice and services contributes to the sustainable development of the agricultural, industrial, infrastructure and other sectors of the Ethiopian economy.
International Organisations and Agencies.
- The IAVCEI Commission on Hazards and Risk links academic research to decision-makers, to reduce the impact of volcanic hazards.
- The Global Volcano Model (GVM) is an international network creating an information platform on volcanic hazard and risk, and is responsible for the volcano component of the biennial UN Global Assessment Report on Disaster Risk Reduction.
Commercial Sector (Public and Private Geothermal Energy)
- Reykjavik Geothermal Limited develops high enthalpy geothermal resources and will construct Africa's largest (1 GW, $4billion) geothermal power plant in our study area.
- Ethiopian Electrical Power Corporation (EEPCO) currently operates a 7MW geothermal power station in our study area, which they are expanding to 70MW.

We will deliver benefit by:
National Government
- Assist Ethiopian scientific partners to build institutional capacity and a volcano monitoring strategy for observations of, and response to, future unrest and eruptions based on information on past eruptions, the processes driving current unrest, and priorities for potential impacts. Enable IGSSA to establish real-time seismic and geodetic monitoring.
- With in-country partners involved in science advice, monitoring, aviation, national and regional administration, and civil protection, ensure our research responds to the needs of all sectors, and make recommendations for the future.
- Research outputs and methodologies supporting effective decision-making under conditions of uncertainty will assist with policy development to strengthen the resilience of people and assets exposed to volcanic hazards. Deliver to local stakeholders advice and a legacy of tools that are practical for use in a developing, low technology nation to determine optimum mitigation and resilience strategies, supporting Ethiopia's national response to the Hyogo Framework for Action international policy for disaster risk reduction. Enable DRMFSS to incorporate volcanic hazards into the local disaster risk profiling exercise.
International Organisations and Agencies
- Through organisations such as the GVM and IAVCEI commission, disseminate our results, share experience and practice applicable in a developing nation, and consult over the development of methodologies to underpin future global-scale analyses of volcanic risk.
- Transfer knowledge and contribute to policy through interaction with the UK Cabinet Office Civil Contingencies Secretariat and input to the National Risk Register.
Commercial Sector
- Collaborate with Rekjavik Geothermal and EEPCO to exchange data that inform geothermal exploration and production, and incorporate hazard analyses specific to rift volcanism to mitigate against potential future economic losses resulting from volcanic activity.

Activities detailed in the Pathways to Impact document will improve monitoring for early warning, facilitate science into policy supporting planning to build resilience, contribute to global data sets and volcanic risk modelling, increase the resilience of industry to support economic development, and facilitate better communities.

Publications

10 25 50

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Ayele A (2015) Seismicity of the central Afar rift and implications for Tendaho dam hazards in Geological Society, London, Special Publications

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Chambers E (2019) Using Ambient Noise to Image the Northern East African Rift in Geochemistry, Geophysics, Geosystems

 
Description The project installed a dense network of earthquake recording instruments (seismometers) on a number of active volcanoes in Ethiopia. The instruments have recorded small earthquakes that are caused by hot fluids breaking the surrounding rocks in the crust as the fluid flows. The position of the earthquakes shows very clearly the fracture and fault systems along which the fluids flow. These fluid filled fracture systems are good targets to drill geothermal wells in order to extract the hot fluids for geothermal energy. We have provided our earthquake results to a geothermal exploration company active in the area, and have been used as part of successful funding proposals to start drilling for geothermal fluids.
Exploitation Route The fluid filled fracture systems that we have discovered are good targets to drill geothermal wells in order to extract the hot fluids for geothermal energy. We have provided our earthquake results to a geothermal exploration company active in the area, and have been used as part of successful funding proposals to start drilling for geothermal fluids at Tulu Moye volcano.
Sectors Energy

URL https://www.mannvit.com/projects/tulu-moye-ethiopia/
 
Description The catalog of earthquakes has been made publicly available and used in multiple geothermal drilling proposals by private industry. The results show regions of fracture permeability and fluid flow in the geothermal system and therefore a good target for geothermal drilling. Drilling targets have been successful and a geothermal power plant is planned for construction by private industry.
First Year Of Impact 2023
Sector Energy
Impact Types Societal

Economic

Policy & public services

 
Description GSNOCS PhD studentship
Amount £35,000 (GBP)
Organisation University of Southampton 
Sector Academic/University
Country United Kingdom
Start 09/2015 
End 10/2018
 
Description GSNOCS PhD studentship
Amount £35,000 (GBP)
Organisation University of Southampton 
Sector Academic/University
Country United Kingdom
Start 03/2015 
End 02/2018
 
Description KAUST research grant
Amount $20,000 (USD)
Organisation King Abdullah University of Science and Technology (KAUST) 
Sector Academic/University
Country Saudi Arabia
Start 03/2016 
End 03/2018
 
Description Spitfire PhD studentship
Amount £70,000 (GBP)
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 09/2015 
End 03/2018
 
Title LiDAR DEM of Boset volcano in Ethiopia 
Description High-resolution light detection and ranging (LiDAR) data of Boset volcano in Ethiopia was collected and processed by the Natural Environment Research Council (NERC) Airborne Research and Survey Facility (ARSF). The data was collected in November 2012 and used to create a digital elevation model (DEM) that has 2 m horizontal and 0.2 m vertical resolution. The LiDAR data was recorded within two swaths. The majority of the data is in a NNE striking swath (30 km length, 5.8 km width) parallel to the rift and a second narrow swath (26.5 km length, 0.75 km width) is across the remnant caldera wall of Gudda volcano. The LiDAR data has been geo-referenced by the NERC ARSF using GPS station ground control points located in the towns of Nazret and Wellenchiti. The file is a .dem file, which is a geospatial file format for storing a raster-based digital elevation model. The data is associated to the RiftVolc project, which is a NERC large grant NE/L013932. When using the data please cite Siegburg et al. (2018) https://doi.org/10.1016/j.jvolgeores.2017.12.014 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
Impact High resolution digital elevation model (DEM) used to quantify rates of fault slip in Ethiopia. The results are of use for seismic hazard analysis and the DEM is of use for geothermal exploration. 
URL https://eprints.soton.ac.uk/439423/
 
Title RiftVolc seismic dataset 
Description The RiftVolc seismic dataset currently consists of continuous seismic data collected at 50 samples per second, from 30 seismic instruments. The completed dataset has been downloaded for the time period February 2016 to October 2017. The dataset is currently stored on the NERC GEF SEIS-UK data management system and will be uploaded for IRIS in one years time, ready for public access at the end of 2020. 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? No  
Impact Earthquakes around Corbetti and Bora have been detected and located using an automatic algorithm. The seismicity levels around Corbetti are low with around ~300 events detected over 18 months. The bulk of these events occur during a swarm in August 2016 south of Corbetti beneath the large city of Awassa. These could be due to the activation of an intra-rift normal fault, similar to the earthquake which occurred during January 2016. In contrast to Corbetti, more than 2000 earthquakes were detected and located during the same period around Bora. These mostly lie in the SE corner of the caldera wall and are shallower than 5 km b.s.l. Their shallow depth suggests that they may be induced by an active geothermal system. However, the b-value is approximately 1, suggesting that these are in fact tectonically induced possibly by a small amount of movement along the caldera faults. 
 
Title Seismicity catalogue of Tulu-Moye volcano 
Description Catalogue of earthquakes from Tulu-Moye volcano during 2016-2017. Earthquakes detected and located using the RiftVolc seismic network, and now published in G-Cubed. 
Type Of Material Database/Collection of data 
Year Produced 2019 
Provided To Others? Yes  
Impact The catalogue was provided to Reykjavik Geothermal and used as part of their drilling proposal for Tulu-Moye. The seismicity shows regions of geothermal fluid permeability. 
URL https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GC007648
 
Description Addis Ababa University - ODA relevant 
Organisation Addis Ababa University
Country Ethiopia 
Sector Academic/University 
PI Contribution The RiftVolc project has provided the funding and equipment and helped to install 2 permanent, real-time seismic stations which are fully linked to the Addis Ababa University national seismic network. The project has also updated the software of the central data hub and provided additional training on the software used in the central hub. Keir has also collaborated directly with the main Ethiopian PI (Dr Atalay Ayele) and his research student on a research paper that is led by the student. The paper is now published in Journal of African Earth Science (see Kibret et al., 2019). Help provided by Keir for the research and writing process will help the student progress to PhD level studies, either in Ethiopia or abroad. In addition, Dr Atalay Ayele was funded through the RiftVolc project to spend 1 month at the University of Southampton during the summer of 2017. During this visit he used the Geophysics group computer network to conduct further work on the frequency content of earthquakes in Ethiopia.
Collaborator Contribution Addis Ababa University have provided significant logistical support for the seismic component of the RiftVolc project. They conducted the visa processing, customs processing on import and export, provided staff support on fieldwork, and provided storage space for the equipment boxes.
Impact The majority of RiftVolc related publications listed in the publications section include the relevant involved staff member from Addis Ababa University. Several publications have also been lead by staff from Addis Ababa University (e.g. Ayele et al., 2016; Lewi et al., 2016; Kibret et al., 2019).
Start Year 2015
 
Description Collaboration with Reykjavik Geothermal - ODA relevant 
Organisation Reykjavik Geothermal Limited
Country Iceland 
Sector Private 
PI Contribution Results generated by Tim Greenfield on the distribution of earthquake activity at Bora volcano in Ethiopia has been used by Reykjavik Geothermal's (RG) efforts to explore for geothermal energy. Earthquake locations and magnitudes of the catalog have been provided to the company and they have used the results to help inform where the rocks are fractured and likely have high permeability. The results have been directly included in a proposal by Reykjavik Geothermal to drill the first exploration well on the volcano. The contribution of the research is summarized by the following statement used in the drilling proposal, "Seismic studies carried out in the area by University of Southampton recorded 1171 events between 26th of February 2016 and 1st of October 2017, all less than 2.5 magnitude, thereof 90 recorded in the desired drilling area, indicating seismically active faults and high permeability". Since June 2019, RG are partners with me and Imperial College London on a follow on project to monitor microseismicity beneath Abaya volcanic field in the Ethiopian rift. They have helped facilitate deployment of 5 seismometers which are scheduled to be in place during June 2019 to June 2021. The results are ODA relevant since drilling activities are key to future development of the geothermal resource and subsequent acquisition of clean electricity in Ethiopia. Microseismicity results for the first year of the project have been completed and will be used by RG in a drilling proposal. In addition, RG are seeking funding to continue our monitoring efforts of the volcanic field. This support includes being a project partners on NERC standard grant submission in Jan 2022 to fund this work.
Collaborator Contribution Reykjavik Geothermal (RG) have provided us with a large GIS database including roads, administrative regions, geological faults, volcanic cones, hotsprings that have been useful in planning where to place seismic recorders, and also helped interpret reasons for the earthquake activity. RG are also actively seeking funding as part of their drilling proposal to continue seismic monitoring efforts beyond June 2021. This support includes being a project partners on NERC standard grant submission in Jan 2022 to fund this work.
Impact Results generated by Tim Greenfield on the distribution of earthquake activity at Bora volcano in Ethiopia has been used by Reykjavik Geothermal's efforts to explore for geothermal energy. Earthquake locations and magnitudes of the catalog have been provided to the company and they have used the results to help inform where the rocks are fractured and likely have high permeability. The results have been directly included in a proposal by Reykjavik Geothermal to drill the first exploration well on the volcano. The contribution of the research is summarized by the following statement used in the drilling proposal, "Seismic studies carried out in the area by University of Southampton recorded 1171 events between 26th of February 2016 and 1st of October 2017, all less than 2.5 magnitude, thereof 90 recorded in the desired drilling area, indicating seismically active faults and high permeability".
Start Year 2017
 
Description Science and Engineering Open Day at the University of Southampton 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Activity - contributed a stand to a Science and Engineering Open Day at the University of Southampton on seismology aimed to inform the public, especially school children, how earthquakes are recorded and how they can be useful to understand natural hazards and resources. More than 100 members of the public and school pupils are estimated to have visited the stand which included a working seismometer and a number of poster displays. The impact of the event has not been quantified.
Year(s) Of Engagement Activity 2016,2017