About this map:

This map shows the extent of the basal and parabasal zones of the NGLA. The source of the geospatial information is the 2013 volcanic basement map, an update of the original 1982 map produced by the Northern Guam Lens Study (CDM, 1982). The work on updating the map utilized geophysical and drilling data to correct and refine our understanding of basement topography and improve the map; see WERI Technical Report #141 (Bendixson, 2013). Details on the methodology used, content, and applications of the map can be found in WERI Technical Report #142 (Vann et al., 2013).