Observations at Costa Rican volcano offer clues to causes of eruptions



Recent measurements of ground deformation at an active volcano show great promise for elucidating the processes that lead to volcanic eruptions. A long-term effort to continuously monitor ground deformation over a very wide bandwidth using state-of-the-art geodetic, seismic, and acoustic instruments at Arenal Volcano in Costa Rica is producing high-quality recordings of harmonic tremor and explosive events and offers an exciting opportunity to explore possible lunar periodicities in volcanic eruptivity.