The relatively small Rotomā Caldera (Rotomā volcanic complex, also spelled Rotoma) is in the Taupō Volcanic Zone in the North Island of New Zealand.

Rotomā Caldera
Rotoma Caldera
Lake Rotomā fills the Rotomā Caldera
Highest point
Elevation	316 m (1,037 ft)
Coordinates	38°05′S 176°35′E
Dimensions
Width	5 km (3.1 mi)
Geography
Rotomā Caldera North Island Show map of New Zealand Rotomā Caldera Rotomā Caldera (North Island) Show map of North Island
Country	New Zealand
Region	Bay of Plenty
Geology
Age of rock	approximately 9,000 years
Mountain type	Caldera
Volcanic region	Taupō Volcanic Zone
Last eruption	7412 BCE
Climbing
Access	State Highway 30 (New Zealand)

Geography

The Rotomā Caldera is located halfway between the city of Rotorua and town of Whakatāne, with its in filling Lake Rotomā being the easternmost in the chain of three volcanic lakes to the northeast of Lake Rotorua. The other two are Lake Rotoiti and Lake Rotoehu.

Geology

It is immediately to the northeast of the area formally called the Haroharo volcanic complex, and now known as the Haroharo Caldera[1] which is now regarded as part of the much larger Ōkataina Caldera ( Ōkataina Volcanic Centre).[2] It is now also usually classified as part of this volcanic structure, but is regarded as the far eastern extension of the Haroharo linear vent zone within the Ōkataina Caldera.[3][4] It is associated with the northern fault boundary zone (Rotoehu Fault, Manawahe Fault, North Rotomā Fault, Braemar Fault, Mangaone Fault) of current rift activity in the Taupō Volcanic Zone. The caldera is likely overlying the former drainage valley that historically Lake Rotorua used before the Rotoiti eruption of the Ōkataina Caldera 47,400 ± 1500 years ago.[5] The Rotomā volcano's most prominent feature Lake Rotomā was formed within the Rotomā caldera when lava flows following a large crater explosion blocked its outlet. The major eruption episodes were about 7412 BCE with about 8 km³ (1.9 cu mi) of material erupted from 3 different magmas from several different vents.[3][4] It is known that the changes in vegetation following the eruption, while significant were short-lived, with pre-eruption forest and mire vegetation recovering to former levels within about 106 years.[6]

References