At present no conclusive link between earthquakes and changes at the Boiling Lake has been determined. However, research suggests that the episode in December 2004 was related to stress changes associated with the M6.3 Les Saintes earthquake on 21st November 2004.
Research suggests that water levels at the lake are maintained by the bubbles of volcanic gases rising through spaces in the rock beneath the lake. When these gases are absent, the water in the lake is no longer being pushed up and the water level falls. The gases are sometimes absent because vents beneath the lake may become blocked.
Another possible cause for a drop in water level is that the rim around the lake may break allowing some of the water to drain out.
Recent changes in lake water levels was noticed between November 2016 and January 2017. During this period water levels, temperature and activity of the lake fluctuated, before maintaining its normal activity by late January 2017. The most recent water level change was in November 2021.
In its normal state of activity, measured temperatures at the edges of the lake are ~90oC, however, occasionally there have been fluctuations in water levels and temperatures in the past. Since 1876 there have been at least eight (8) recorded instances of changes in the water levels and activity of the Boiling Lake.
The Boiling Lake is a volcano-hydrothermal feature located in an area next to the Valley of Desolation in southern Dominica. The lake is roughly 60m in diameter and approximately 15m deep. The Boiling Lake is the second largest feature of its kind in the world with the largest being Frying Pan Lake in New Zealand. The Valley of Desolation and the Boiling Lake itself are considered sites of interest for locals and visitors to Dominica. They have been part of the Morne Trois Pitons National Park, a UNESCO World Heritage Site since 1987.
The UWI-SRC monitors the Boiling Lake as part of its volcano monitoring programme in Dominica. The UWI-SRC updates the Office of Disaster Management (ODM) when significant changes are observed.
The UWI-SRC suggests contacting the Forestry, Wildlife & Parks Division before visiting the lake at all times. When lake water levels are normal it is generally safe to visit. However, visiting the lake when it is drained may pose some risk. If visiting the lake when it is drained is absolutely necessary, scientists recommend that people exercise extreme caution. Specifically, it is recommended that:
1) No one descends to the water’s edge; absolutely no swimming in the lake and
2) Visitors to the Boiling Lake-Valley of Desolation area avoid approaching the Lake and/or spend as little time as possible at the viewing point on the crater rim.
Significant drops in water levels at the Boiling Lake may increase the potential hazards to visitors to the Boiling Lake- Valley of Desolation area due to the increased risk of small steam and gas explosions. In 1901 a small steam and gas explosion from the Boiling Lake (which was almost empty at the time), released harmful gases (probably mainly carbon dioxide, a colourless and odourless gas) and killed two people who were at the water’s edge at the time. The Valley of Desolation has seen two phreatic (steam) eruptions within recent history; on January 4th, 1880 and again on July 9th, 1997.
Based on current research the draining of the lake does not necessarily mean that a volcanic eruption will occur. Scientists at the UWI-Seismic Research Centre (UWI-SRC) are continually monitoring all of Dominica’s volcanoes and will communicate any changes in activity to the ODM.
Across the many geothermal developments in the world there has never been a case of a geothermal well triggering a volcanic eruption.