Danan was one of the three volcanic cone

Volcanic cone

Volcanic cones are among the simplest volcanic formations. They are built by ejecta from a volcanic vent, piling up around the vent in the shape of a cone with a central crater. Volcanic cones are of different types, depending upon the nature and size of the fragments ejected during the eruption...

s (the others being Perboewatan

Perboewatan

Perboewatan was one of the three main volcanic cones on the island of Krakatoa , in the Sunda Strait, in Indonesia. It was the lowest and northernmost of the cones...

 and Rakata

Rakata

Rakata is a collapsed stratovolcano of the Indonesian island of Krakatoa in the Sunda Strait between the islands of Sumatra and Java. Standing tall, it was the largest and southernmost of three volcanoes that formed the island Krakatoa and the only one not totally destroyed in the eruption of 1883...

) on the island of Krakatoa

Krakatoa

Krakatoa is a volcanic island made of a'a lava in the Sunda Strait between the islands of Java and Sumatra in Indonesia. The name is used for the island group, the main island , and the volcano as a whole. The island exploded in 1883, killing approximately 40,000 people, although some estimates...

, in the Sunda Strait

Sunda Strait

The Sunda Strait is the strait between the Indonesian islands of Java and Sumatra. It connects the Java Sea to the Indian Ocean...

, in Indonesia

Indonesia

Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

. It stood 450 metres (1,476.4 ft), laid in the central area of the island, and may have been a twin volcano

Volcano

2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

. Danan was virtually destroyed in the 1883 eruption of Krakatoa

1883 eruption of Krakatoa

The 1883 eruption of Krakatoa began in May 1883 and culminated with the destruction of Krakatoa on 27 August 1883. Minor seismic activity continued to be reported until February 1884, though reports after October 1883 were later dismissed by Rogier Verbeek's investigation.-Early phase:In the years...

, only a rocky islet named Bootsmansrots remains of it.

Form

Not much can be found about Danan; the interior of Krakatoa was little explored or surveyed. There were several peaks, and Verbeek surmised that it formed a "ring-shaped crater wall". In one of the photographs of Perboewatan erupting in May 1883, Danan's irregular shape can be seen in the background, partially obscured by the ash cloud arising from Perboewatan.

1680–1681 eruption

Danan apparently joined Perboewatan in eruption sometime after May, 1680, when Perboewatan started erupting. A returning Dutch traveler saw both cones erupting in February, 1681.

The 1883 eruption

Perboewatan started erupting in May 1883. In June, a black cloud hung over the islands for five days, and when it lifted on June 24, an ash column could be seen issuing apparently from an area between Perboewatan and Danan. By the time Captain Ferzenaar visited the island on August 11, Danan was in full eruption and there were about a dozen steam plumes, most of which were between the two cones. The two cones continued erupting, entering the cataclysmic phase on August 26, with four terminal events on the morning of the 27th.

Rogier Verbeek

Rogier Verbeek

Rogier Diederik Marius Verbeek was a Dutch geologist and nature scientist.His journal Krakatau, which was edited in 1884 and 1885 by order of the Governor-General of the Dutch East Indies, is his most known work. It deals with the eruption of the volcanic island Krakatoa in 1883 and brought...

's reconstruction of the eruption has Danan destroyed at about 10:52 am, August 27 in the last of the castastrophic explosions.

Bootsmansrots

Bootsmansrots ('Bosun's Rock' in Dutch) is a small (about 10 m squared) platform of rock composed of parallel

Parallel (geometry)

Parallelism is a term in geometry and in everyday life that refers to a property in Euclidean space of two or more lines or planes, or a combination of these. The assumed existence and properties of parallel lines are the basis of Euclid's parallel postulate. Two lines in a plane that do not...

 slabs of hypersthene

Hypersthene

Hypersthene is a common rock-forming inosilicate mineral belonging to the group of orthorhombic pyroxenes. Many references have formally abandoned this term, preferring to categorise this mineral as enstatite or ferrosilite. It is found in igneous and some metamorphic rocks as well as in stony and...

 andesite

Andesite

Andesite is an extrusive igneous, volcanic rock, of intermediate composition, with aphanitic to porphyritic texture. In a general sense, it is the intermediate type between basalt and dacite. The mineral assemblage is typically dominated by plagioclase plus pyroxene and/or hornblende. Magnetite,...

 tilted at about a 45-degree angle to the sea surface. It probably was an extrusion

Extrusion

Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed or drawn through a die of the desired cross-section...

 dike

Dike (geology)

A dike or dyke in geology is a type of sheet intrusion referring to any geologic body that cuts discordantly across* planar wall rock structures, such as bedding or foliation...

in the flank of Danan and was stable enough to keep Danan from being destroyed in the major explosion at 10:02 am which destroyed the area to the south and the northern half of Rakata. The steep angle to the west indicates that it has moved from its original location, probably by the bulk of Danan collapsing in that direction.