Davidof Volcano

Since the island is uninhabited, very little transportation is available. Transport can be found in Adak, albeit that the town is 199 miles (320 km)[2] from the island.[2]

Because of the inclusion of Alaska, the United States has the largest number of active volcanoes in the world, many of them geologically young.[3] In Alaska, at least 50 volcanoes, including those in the Aleutian archipelago, have erupted in historical time.[4] Alaska accounts for about 80% of the United States' volcanoes, excluding the seamounts in the area, about 8% of the world's volcanoes, and most of these are located among the Aleutian Islands.[4] The Aleutian Arc forms the northern boundary of the Pacific Ring of Fire,[4] where tectonic activity generates earthquakes and volcanic eruptions regularly.

The largest of four tiny islands in the "Aleutian Krakatau" caldera,[5] Davidof is a stratovolcano[5] and caldera remnant[1] of a larger stratovolcano, which presumably collapsed at the end of the Cenozoic period.[2] In all, the caldera extends for 262 feet (80 m) underwater.[5] Davidof Island's shape is abstract, with many inclining, steep features and several sea cliffs.[6] There are no visible water features.[6]

Davidof's exact composition is unknown, although studies conducted by W.H. Nelson of the United States Geological Survey (USGS) determined that the lava, at least, was layered over a base of red breccia. The lavas appeared to be differentiating, but stuck to gray color with either "glassy or fine-grained, compact or dikty-taxitic" composition.[7] Much like Segula Island, all of Davidof's lava and even pyroclastic deposits interact by overlapping with each other.[7] The uppermost layer of these deposits is formed by the pyroclastic flow deposits.[7] The lava is filled with phenocrysts like feldspar, olivine, and pyroxene, and these can be found easily about the lava areas.[7]

Despite its small size, Davidof is heavily vegetated,[1] with variations of moss, lichen, and heath.[9] Spread throughout the island are grass and sedges, which cover much of the lower surface.[9] Fungi, liverworts, horsetails, and ferns, can be found on the island, along with flowering plants, such as the narcissus anemone, lupines, and orchids. Seaweed is also common on the island's beaches.[9]