Their capability to penetrate large depths of material renders high-energy atmospheric muons a unique probe for geophysical explorations. Provided the topography of the target is known, the measurement of the attenuation of the muon flux permits the cartography of matter density distributions revealing spatial and possibly also temporal variations in extended geological structures. A collaborat...

Natural geohazards, such as earthquakes, volcanic eruptions, landslides, and volcanic collapse, are of immediate societal concern. In an oceanic setting (Fig. 1), all are capable of generating tsunami that threaten coastal zones at distances of many thousands of kilometers. This power and its effects were forcefully shown by the giant earthquake (� w 9.2) and tsunami of 26 December 2004 off t...

Volcanic lakes within calderas should be viewed as high-risk systems, and an intensive lake monitoring must be carried out to evaluate the hazard of potential limnic or phreatic-magmatic eruptions. In Ecuador, two caldera lakes – Lakes Quilotoa and Cuicocha, located in the high Andean region >3000 a.s.l. – have been the focus of these investigations. Both volcanoes are geologically young or his...

Volcanic exposure implies multiple hazards for human settlements. The identification of the potential that volcanic activity can entail is a challenge requiring assessing specific situations determined place would face. Popocatépetl, volcano in centre México, represents significant hazard source, and it located within densely populated region with more than 20 million people. Despite existence ...

Eruption forecasting is a major goal in volcanology. Logically, but unfortunately, forecasting hazards related to non-magmatic unrest is too often overshadowed by eruption forecasting, although many volcanoes often pass through states of non-eruptive and non-magmatic unrest for various and prolonged periods of time. Volcanic hazards related to non-magmatic unrest can be highly violent and/or de...

Satellite measurements of volcanic sulfur dioxide (SO2) emissions can provide critical information for aviation hazard mitigation, particularly when ash detection techniques fail. Recent developments in space-based SO2 monitoring are discussed, focusing on daily, global ultraviolet (UV) measurements by the Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite. OMI’s high sensitivity to SO2...

Repeated aircraft hazards in Alaska related to volcanic clouds have resulted in the use of a mobile C-band radar devoted to volcanic-cloud monitoring. The radar is located at Kenai, in range of several volcanoes in the Cook Inlet area. Three significant eruptions from the Crater Peak vent of Mount Spurr volcano (about 80 km from Kenai) in 1992 provided the first tests of the radar. The system c...

Forecasting is a central goal of volcanology. Intensive monitoring of recent eruptions has generated integrated timeseries of data, which have resulted in several successful examples of warnings being issued on impending eruptions. Ability to forecast is being advanced by new technology, such as broad-band seismology, satellite observations of ground deformation and improved field spectrometers...