RAPID: Hot spring microbial response to magma intrusion at Fagradalsfjall volcano, Iceland

On March 19, 2021 Fagradalsfjall volcano, near Reykjavik Iceland, began erupting, resulting in a new and prominent fissure. Volcanic eruptions release volatile gases underground that make their way to hot springs on the Earth's surface. The purpose of this RAPID project is to sample and analyze the microbial communities in the hot springs near the volcano.

The PI and her team will employ a recently developed approach to track hot spring microbes and their activities on continental-scales. They will sample microbial communities across many different geothermal hot springs along a geological gradient, using a broad suite of simultaneously-collected geochemical measurements. A rapid response is necessary to take these samples during active volcanic activity.

The work is being coordinated with collaborators in Iceland and will enhance international scientific collaboration. Video of the expedition will be shared via social media and in public presentations.

The PI and her team have demonstrated that measuring a large number of geochemical constituents (e.g., carbon and nitrogen isotopes, metals, and noble gases in the aqueous, gas, and solid phases) and microbiological data (16S rRNA gene amplicon libraries, metagenomes, metatranscriptomes, and cell counts), enabled microbial community compositions and functions to be linked to the most salient geochemical factors for each part of the community. Beneath the Fagradalsfjall volcano, seismic activity indicates that magmas are injected along a NE-SW trending fault system, where abundant natural hot springs occur.

This project will test the hypothesis that the microbial communities in hot springs near the volcanic activity will experience more pronounced reactions to volatile fluxes than those in distal hot springs. By sampling hot springs variably influenced by the nearby magmatic intrusions, microbial ecosystems will be tracked across a gradient of volatile influence.

Since these expulsions are short-lived, the sampling campaign is extremely time-sensitive. This study will have unprecedented access to a gradient of nascent magmatic disturbances to hydrothermal ecosystems. It will link hot spring microbial communities with the deep subsurface nutrients that may drive them, which has not yet been explored in a plume-driven continental rift.

Filmed products of the expedition and scientific studies will be shared via social media and outreach with the public.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.