WaterTalk: Extreme gas pressures in lakes: from the "killer" Lake Nyos (Cameroon) to Guadiana Pit Lake (Spain) and Lake Kivu (Rwanda and DR Congo)

Tuesday, July 26, 2022 1:00 pm - 2:00 pm EDT

WaterTalks

As part of the Water Institute's WaterTalks lecture series, Bertram BoehrerHelmholtz Centre for Environmental Research - UFZ, Magdeburg, Germany, will present: Extreme gas pressures in lakes: from the "killer" Lake Nyos (Cameroon) to Guadiana Pit Lake (Spain) and Lake Kivu (Rwanda and DR Congo).

This event will be offered in person on the University of Waterloo campus in DC 1302 and online via Zoom.


More information

Several lakes show extreme loads of gases in their deep water. If those gases exert a gaspressure close to absolute pressure, bubbles can form. When the volume of potentially released gases is high, the situation must be assessed for the risk of large scale ebullition. In 1986, about 1700 humans died in the carbon dioxide released from the deep lake waters of Lake Nyos.

We report, how reliable measurements of extreme gas loads can be accomplished [1]. In the case of Lake Kivu 40 billion m³ of exploitable methane could be substantiated and the idustrial exploitation for power generation has started. In Guadiana Pit Lake carbon dioxide loads of nearly 3 liters of gas per liter of lake water were detected [2]. We report about possibilities to confirm high gas loads by direct measurements of gas pressure or sound speed [3]. In the case of Guadiana Pit Lake, authorities followed the recommendation to remove the gas load artificially to avert the danger of a limnic eruption [4], while in the case of Lake Kivu prescriptions for the survey of the lake have been issued by an international expert team for the period of methane exploitation.

[1] Boehrer et.al. (2019):  Reliable reference for the methane concentrations in Lake Kivu at the beginning of industrial exploitation. Hydrol. Earth Syst. Sci. 23 (11), 4707 – 4716. [2] Boehrer et.al. (2016):  Quantifying, assessing and removing the extreme gas load from meromictic Guadiana pit lake, Southwest Spain. Sci. Total Environ. 563-564 , 486 – 477. [3] Boehrer et.al. (2021): Carbon Dioxide in Lake Nyos, Cameroon, estimated quantitatively from sound speed measurements. Front. Earth Sci. 9, 645011. [4] Sánchez‑España et.al. (2020): Degassing pit lakes: Technical issues and lessons learnt from the HERCO2 project in the Guadiana open pit (Herrerías mine, SW Spain). Mine Water Environ. 39 (3), 517 – 534.

Speaker bio

Bertram
Dr. Bertram Boehrer is a senior scientist and work group leader of “Limnophysics and Lake Modelling” at Helmholtz Centre for Environmental Research – UFZ, Magdeburg, Germany. His research fields include stratification of lakes, meromixis, extreme gas pressures in lakes, properties of limnic waters, modelling water quality in lakes, environmental fluid dynamics, field measurements in lakes, etc. Since 2010, Dr. Bertram Boehrer has been teaching staff at the Faculty of Physics and Astronomy of the University of Heidelberg and teaches an annual block course “Physical Limnology”.

Dr. Bertram Boehrer finished his tertiary physics education at Heidelberg University from 1984 to 1990, earned Masters at the Institute for Environmental Physics of the Univ. of Heidelberg and the Limnological Institute Konstanz from 1989 to 1990 and his Ph.D. at the University of Western Australia, Centre for Water Research from 1991 to 1996. He did Postdoc research in UFZ-section Inland Waters from 1996 to 1998.

He has been leading the scientific committee, Workshop on Physical Processes in Natural Waters since 2016 and Co-chaired the Physical Limnology work group of International Society of Limnology (SIL). He has been a member of the Expert Advisory Board at the Lake Kivu Management Programme (Rwanda, Africa) and a member in several scientific organizations: DPG (environmental physics), AGU (Americal Geophysical Union), ASLO (Association for the Sciences of Limnology and Oceanography), DGL (German Society of Limnology), SIL International Society for Limnology), International PhD referee, etc.


The University of Waterloo is committed to achieving barrier-free accessibility for persons with disabilities who are visiting, studying or working at Waterloo. If you have questions concerning access or wish to request accommodations for this event, please contact Julie Grant (j26grant@uwaterloo.ca)