BackgroundThe caldera consists of an older western and younger eastern part. Ponded lava flows and pyroclastic deposits fill the floor of the western caldera, whose SW side is cut by a fresh-looking smaller crater.
The 2-km-wide eastern portion of the caldera contained a steep-walled inner crater whose floor prior to the 2003 eruption was only 68 m above sea level. A submarine volcano, named NE Anatahan, rises to within 460 m of the sea surface on the NE flank of the volcano, and numerous other submarine vents are found on the NE-to-SE flanks.
Sparseness of vegetation on the most recent lava flows on Anatahan had indicated that they were of Holocene age, but the first historical eruption of Anatahan did not occur until May 2003, when a large explosive eruption took place forming a new crater inside the eastern caldera. (Smithsonian / GVP)
See also: Sentinel hub | Landsat 8