This book aims to give an overview on the present state of volcanic lake research, covering topics such as volcano monitoring, the chemistry, dynamics and degassing of acidic crater lakes, mass-energy-chemical-isotopic balance approaches, limnology and degassing of Nyos-type lakes, the impact on the human and natural environment, the eruption products and impact of crater lake breaching eruptions, numerical modeling of gas clouds and lake eruptions, thermo-hydro-mechanical and deformation modeling, CO2 fluxes from lakes, volcanic lakes observed from space, biological activity, continuous monitoring techniques, and some aspects more. We hope to offer an updated manual on volcanic lake research, providing classic research methods, and point towards a more high-tech approach of future volcanic lake research and continuous monitoring.

Volcanoes sometimes host a lake at the Earth's surface. These lakes are the surface expressions of a reservoir, often termed a hydrothermal system, in highly fractured, permeable and porous media where fluids circulate. They can become monitoring targets since they integrate the heat flux discharged by an underlying magma body and condense some volcanic gases. Since they trap volcanic heat and gases, they are excellent tools to provide additional information about the status of a volcano and volcanic lake-related hazards. This Special Publication comes at an exciting time for the volcanic lake community. It brings together scientific papers, which include studies of their structure, hydrogeological modelling, long-term multi-disciplinary monitoring efforts, as well as a number of innovative methods of sampling, data acquisition and in situ and laboratory experiments. Several papers challenge long-established paradigms and introduce new concepts and terminologies. This collection of papers will be a useful reference for researchers dealing with volcanic lakes and more generally with hydrothermal systems, phreatic/hydrothermal eruptions and wet volcanoes.

On Earth, lakes provide favorable environments for the development of life and its preservation as fossils. They are extremely sensitive to climate fluctuations and to conditions within their watersheds. As such, lakes are unique markers of the impact of environmental changes. Past and current missions have now demonstrated that water once flowed at the surface of Mars early in its history. Evidence of ancient ponding has been uncovered at scales ranging from a few kilometers to possibly that of the Arctic ocean. Whether life existed on Mars is still unknown; upcoming missions may find critical evidence to address this question in ancient lakebeds as clues about Mars’ climate evolution and its habitability potential are still preserved in their sedimentary record. Lakes on Mars is the first review on this subject. It is written by leading planetary scientists who have dedicated their careers to searching and exploring the questions of water, lakes, and oceans on Mars through their involvement in planetary exploration, and the analysis of orbital and ground data beginning with Viking up to the most recent missions. In thirteen chapters, Lakes on Mars critically discusses new data and explores the role that water played in the evolution of the surface of Mars, the past hydrological provinces of the planet, the possibility of heated lake habitats through enhanced geothermal flux associated with volcanic activity and impact cratering. The book also explores alternate hypotheses to explain the geological record. Topographic, morphologic, stratigraphic, and mineralogic evidence are presented that suggest successions of ancient lake environments in Valles Marineris and Hellas. The existence of large lakes and/or small oceans in Elysium and the Northern Plains is supported both by the global distribution of deltaic deposits and by equipotential surfaces that may reflect their past margins. Whether those environments were conducive to life has yet to be demonstrated but from comparison with our planet, their sedimentary deposits may provide the best opportunity to find its record, if any. The final chapters explore the impact of climate variability on declining lake habitats in one of the closest terrestrial analogs to Mars at the Noachian/Hesperian transition, identify the geologic, morphologic and mineralogic signatures of ancient lakes to be searched for on Mars, and present the case for landing the Mars Science Laboratory mission in such an environment. First review on the subject by worldwide leading authorities in the field New studies with most recent data, new images, figures, and maps Most recent results from research in terrestrial analogs