a r t i c l e i n f o An evaluation of the historical record of volcanic eruptions shows that subaerial volcanism increases globally by two to six times above background levels between 12 ka and 7 ka, during the last deglaciation. Increased volcanism occurs in deglaciating regions. Causal mechanisms could include an increase in magma production owing to the mantle decompression caused by ablati...

Geochemical analyses of stratigraphic sequences of lava flows are necessary to understand how a volcano works. Typically one sample from each lava flow is collected and studied with the assumption that this sample is representative of the flow composition. This assumption may not be valid. The thickness of flows ranges from <1 to >100 m. Geochemical heterogeneity in thin flows may be created by...

Basalts erupted to form the atolls and guyots of the Western Pacific have been altered in various ways, ranging from hydrothermal alteration to subaerial weathering by meteoric waters in a tropical environment. Subaerial weathering has been moderate to extreme. Moderate subaerial weathering is expressed by dissolution or replacement of primary minerals (olivine, pyroxenes, plagioclase feldspar)...

A re-investigation of subaerial parts of Leontodon cichoraceus (Ten.) Sanguin. yielded the new germacrane-type sesquiterpenoid 15-beta-D-glucopyranosyl-8-[p-(beta-D-glucopyranosyloxy)phenylacetyl]-salonitenolide. The structure was established by APCI mass spectrometry and 1D- and 2D-NMR spectroscopy. A survey by HPLC-DAD and HPLC-MS gave no signs of this compound in 23 other taxa of Leontodon.

Knowledge of the global distribution Earth volcanism is critical in many fields Geosciences involving large-scale assessments, such as plate tectonics, volcanic hazards, and climate change. Recent analysis has revealed that eruption inter-event times are exponentially distributed, implying on scale eruptions Poisson distributed. Here, we employ those findings to calibrate a continuous frequency...