Flow front map at 1:12,000 scale

This map uses a satellite image acquired in March 2014 (provided by Digital Globe) as a base to show the area around the front of the June 27th lava flow. The area of the flow on October 25, 2014, at 5:00 PM is shown in pink, while widening and advancement of the flow as mapped on October 26 at 12:30 PM is shown in red. The dotted blue lines show steepest-descent paths in the area, calculated from a 1983 digital elevation model (DEM). The latitude and longitude of the front of the narrow finger of lava advancing toward Pāhoa was 19.492276, -154.956200 (Decimal Degrees; WGS84).

The flow advanced about 190 meters (210 yards) during the preceding 19.5 hours, traveling completely through the cemetery above Pāhoa. At the time of mapping, the flow was 715 meters (780 yards) directly upslope from Pāhoa Village Road. The flow was advancing downslope between two intersecting steepest-descent paths and was trending toward the southern one. The flow will likely return to the original steepest-descent path about 300 m (330 yd) upslope from Pāhoa Village Road, if it continues.

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 dotted blue lines can be used to infer only approximate flow paths. For calculation details, see http://pubs.usgs.gov/of/2007/1264/.