Recent changes in hydrothermal dynamics at the Boiling Lake, Dominica: Implications for Instability, Gas Release, and Volcanic Hazards
^^ Erouscilla Joseph^^ 1, Holli Frey 2, Racine Basant 1 and Richard Robertson 1
Affiliations: 1 UWI Seismic Research Centre, St. Augustine, Trinidad and Tobago 2 Department of Geosciences, Union College, Schenectady, NY, USA
Presentation type: Talk
Presentation time: Friday 08:45 - 09:00, Room S150
Programme No: 6.8.2
Abstract
Since 1900, the Boiling Lake in Dominica has experienced at least ten instances of rapid draining and refilling, reflecting instability in its hydrothermal system. During these disturbances, harmful gases like carbon dioxide can be released suddenly and small steam explosions may occur, which pose hazards to visitors to the lake. After a Mw6.3 earthquake in 2004, ~40 km north of Dominica, the lake underwent a period of instability from December 2004 to April 2005. The lake's chemistry also shifted from an acidic to a more neutral composition, a change that has since not been reversed. These episodes of instability, observed more frequently in recent decades, suggest significant local changes in the volcano-hydrothermal system. Recent research indicates that water levels are maintained by volcanic gas bubbles rising through cracks in the lake's bedrock. When these vents are blocked---due to landslides or other disruptions---the water level falls as gas is no longer released. Improved monitoring utilizing thermal and satellite imagery provides an opportunity to reassess the processes driving these episodes. This research aims to enhance the hydrogeochemical model of the lake, offering better insights into the mechanisms of instability and helping to improve the understanding of volcanic hazards at the lake.