Large scale orthophoto map

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 Kīlauea's active East Rift Zone lava flow. The area of the flow on December 19 at 8:30 AM is shown in pink, while advancement of the flow as mapped on December 22 at 3:00 PM is shown in red.
Advancement of the flow continued at a slower rate, compared to last week, and the flow moved about 265 meters (290 yards) since Friday's mapping. A southern branch of the flow on this map, following the main steepest-descent path is stalled. The more northerly advancing branch was 30 meters (33 yards) from the fire break road and 675 meters (738 yards) away from the back of the Pāhoa Marketplace, measured in a straight line. Tick marks show distance above Pāhoa Marketplace measured along the main steepest-descent path.
The blue line shows the dominant steepest-descent path for the drainage the lava flow is following, 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 line on this map can be used to infer only an approximate flow paths.