Kīlauea ERZ Fissure Map with Paths of Steepest Descent, May 9

This map shows the locations of fissures and an ‘A‘ā flow erupted since May 3 in the order that they occurred in Leilani Estates as of 7:00 p.m. HST, May 8. The purple areas are lava flows erupted in 1840, 1955, 1960, and 2014-2015. The blue lines are paths of steepest descent that identify likely paths of a lava flow, if and when lava moves downhill from an erupting vent. The paths of steepest-descent were calculated from a 1983 digital elevation model (DEM) of the Island of Hawai'i, created from digitized contours. Steepest-descent path analysis is based on the assumption that the DEM perfectly represents the earth's surface. DEMs, however, are not perfect, so the blue lines on this map can be used to infer only approximate lava-flow paths. The base shaded-relief map was made from the 1983 10-m (DEM). For additional explanation of steepest descent paths, see http://pubs.usgs.gov/of/2007/1264. For calculation details, ESRI shapefiles, and KMZ versions of steepest descent paths, see https://www.sciencebase.gov/catalog/item/57fd072ee4b0824b2d130eb5.