Volcano Watch: From macro to micro: How island rocks tell their stories

  • USGS Photos by K.J. Lynn Left: Example of tephra deposits as they appear in the field. At this macro step, field geologists take notes and make detailed descriptions of the samples before collecting material for further study. Middle: A laboratory-prepared mount of volcanic glass in clear epoxy that has been polished for geochemical analysis. Right: A microscopic view of one of the volcanic glass grains from the middle photo (outlined in red), taken using a high-powered microscope.

Like the pages of a book, the stories of Hawaiian volcanoes are “written” in layers of rock. When Hawaiian Volcano Observatory scientists collect and study volcanic samples, the rocks and minerals go through several stages of preparation and analysis that allow scientists to “translate” the encoded stories.