Summary
Highlights
Alberto Vitale Brovarone introduces the Deep Seep project, which investigates hidden energy sources, particularly geological hydrogen. He explains that traditional geological and geochemical studies often overlook the energy potential of molecules like molecular hydrogen in the deep Earth. The project aims to understand how these energy sources form, move through the crust and mantle, interact with rocks, and potentially reach the biosphere, particularly to feed microbial life in the subsurface.
A key lesson learned is that molecular hydrogen is prevalent in areas where it is expected, even in old Precambrian continental crust like in Greenland. Despite initial plans changing, hydrogen was found everywhere in the new exploration area, not as diffused emissions, but preserved within the rocks, indicating past presence in rock porosity and fluids over geological time. This suggests hydrogen is common when and where one looks for it.
The expedition encountered a vast variety of rocks, from sedimentary to igneous, and from felsic to ultramafic compositions, making the Precambrian basement diverse and complex. These rocks, ranging from 3 billion to 1.2 billion years old, differed significantly in their potential to produce hydrogen during their formation or aging, and reflected multiple stages of Earth's evolution, including continental crust creation and mountain-building events.
The research focuses on developing methods to detect past hydrogen presence in volatile geological fluids, as hydrogen is very elusive. Unlike water, for which metamorphic or alteration reactions clearly indicate its presence, a similar understanding for hydrogen is still lacking. The team is not focusing on specific minerals but testing hypotheses based on various rock types and potential reactions, using field-based sampling strategies and intuitive questions to guide their search for hydrogen traces.
While extraction benefits from the oil and gas industry's knowledge, the project prioritizes bias-free fundamental research. Greenland, with its high share of renewable energy sources and logistical challenges for hydrogen transport, is not ideal for immediate hydrogen extraction but serves as an excellent location for fundamental research. This allows for unbiased study of hydrogen formation and migration, independent of economic or industrial pressures.
During fieldwork, a makeshift device was created to attempt preliminary hydrogen analysis by crushing rocks, but it ultimately failed due to its rudimentary nature. The experience, however, motivated a shift in sampling strategy. For laboratory confirmation, Raman spectroscopy is the easiest technique, allowing rapid detection of hydrogen in fluid inclusions within rock thin sections. Further investigations will utilize a broad range of techniques, from microstructures to chemical analysis and modeling, to comprehensively understand deep hydrogen systems.
The origin of hydrogen is complex, with several potential processes. Magmatic or late magmatic processes, especially in younger igneus systems (1.2 billion years old), can lead to hydrogen formation. Aqueous alteration of iron- or redox-sensitive element-bearing rocks is another possibility. Radiolysis, and thermogenic maturation of organic matter are also considered plausible, covering nearly the entire range of known hydrogen-forming processes.
The expedition faced significant last-minute changes due to drift ice, forcing the team to devise new plans rapidly, download geological maps, and explore a different area with many unknowns. Despite the stress, this adaptability led to discovering surprising rock diversity. Discrepancies between historical geological maps and field observations were also encountered, highlighting the evolving understanding of remote areas and providing valuable learning experiences about reconstructing geological ideas.
Greenland's high fieldwork costs necessitated a restrictive schedule, maximizing sampling objectives. Unlike the Alpine regions, Greenland's vast, treeless outcrops present overwhelming amounts of geological information, making decisions on where to stop, what to skip, and which samples to collect exceptionally challenging. The vastness requires significant experience to navigate efficiently.
While Greenland currently has abundant renewable energy, natural hydrogen could become an important local resource for remote villages, despite challenges in transport to other countries. The fragility of the Arctic environment makes the self-government cautious about exploration and extraction, and while technical feasibility is uncertain, environmental considerations are paramount.
Many unexpected geological features were encountered. An early discovery of uncommon structures in a rock, previously associated with hydrogen in other regions, was particularly surprising. While these structures in Greenland were not directly linked to hydrogen, hydrogen was still present in the rock, posing new questions. One of the most rewarding moments was a relaxed, unplanned midnight fieldwork session, which captured the unique beauty and challenge of working in Greenland.
The speaker's future research focuses on uncovering more about natural hydrogen, which he views as a '12th player' in Earth's history—an invisible, transparent element that profoundly impacts geological processes, making previous explanations incomplete. He hopes natural hydrogen will become a future energy source, emphasizing its widespread presence despite business and economic complexities. He advocates for careful, evidence-based sharing of findings to properly inform the scientific community and public about hydrogen's potential.