This large-scale map shows the distal part of Kīlauea’s active East Rift Zone lava flow in relation to nearby Puna communities. The area of the flow on February 5 is shown in pink, while widening and advancement of the flow as of February 10 is shown in red.

The blue lines show steepest-descent paths calculated from a 1983 digital elevation model (DEM; for calculation details, see http://pubs.usgs.gov/of/2007/1264/). 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 flow paths. The yellow line marks the active lava tube (the tube continues downslope but has not been mapped).