Wikipedia states, “Mount Vesuvius is a somma-stratovolcano located on the Gulf of Naples, Italy, about 9 km east of Naples and a short distance from the shore. Vesuvius consists of a large cone partially encircled by the steep rim of a summit caldera caused by the collapse of an earlier and originally much higher structure.” A caldera is a cauldron shaped depression caused by the implosion of the top of the cone. Mount Somma is an integral part of the Somma-Vesuvius volcanic complex. It is 1,132 metres (3,714 ft) high.
Mt. Somma the semi-circular shaped range with
Mt. Vesuvius in the centre.
Mount Somma is the remnant of a large volcano, out of which the peak cone of Mount Vesuvius has grown. Currently, Mount Somma appears to be spread in a semicircle around the north and northeast of Vesuvius.
About the etymology of the names Somma and Vesuvius Edward Moor stated in his book ‘Oriental Fragments’ in 1854, “Soma, or Somma, be it remembered, is a name of Vesuvius ; a truly Siva-ic mount or rather of its parent; for Vesuvius is by some authorities reckoned the summit or cone only – Soma as the base, and the older name.”
Edward Moor saw a link between the naming of the Mt. Somma of Naples and Mt. Soma on the Sumbawa island of Sumatra as well as alink with the lore of Vedic god Lord shiva. He stated, “In Sanskrit Soma-bhava would mark the parental relationship; and such is the name currently altered to Sambawa of one of the most active and energetic of existing volcanoes one of, perhaps, ten times the potency and terrific extent of destructiveness of Vesuvius. I now speak of Sambawa, as described by Sir Stamford Raffles and others, in the eastern seas, where this lunar parentage seems extensive including,
perhaps, Sumatra.” Mt. Sambhawa is now known as Mt. Tambora located on the Sumbhawa island of Indonesia. Soma is also Sanskrit for moon, and Shiva is known as Somanath, or lord of the moon.
Prior to the eruption of 79 AD, Mount Vesuvius had a long historic and mythical tradition. The mountain was considered a divinity, and was related with serpent imagery. This has been seen preserved in the frescoes from Pompeii. In the Vedic tradition the serpent Vasuki, dedicated to Lord Shiva or Somanath, is his constant companion. In the saga of the churning of the Ocean of Milk, Mount Mandara was used as the churning rod, and Vasuki, the nagaraja or ‘King of Serpents’ who abides on Shiva’s neck, became the churning rope.
During the churning Vasuki emitted poisonous flames from its mouth and perhaps that corresponds to the lava emitting from Mt. Vesuvius. In Roman mythology it is said that the Romans regarded a serpent called Vesuvius as a devotee of the demigod Hercules and it was after the snake that the mountain was named.
The etymology of the name is explained by various words such as the Indo-European root ‘eus’ meaning shine, or root ‘wes’ meaning ‘hearth’. Both these words appear in Sanskrit as ‘as’ (अस) or ‘light’, and ‘vasa’ (वास) ‘dwell’. The semi-circular shape of Mt. Somma can be equated with the semi-circular or half-moon that appears in the locks of Shiva.
Somma is the older name of the entire mountain.
After the eruption of 79AD the centre cone collapsed.
It is then the name Vesuvius was given to it.