Avachinsky Volcano | John Seach

john

(Avacha, Avachinskaya Sopka)

Kamchatka, Russia

53.255 N, 158.830 E
summit elevation 2751 m
Stratovolcano

Avachinsky volcano is located 25 km NE of Petropavlovsk-Kamchatskiy, Kamchatka's largest city, in southern Kamchatka. The volcano is of the Somma-Vesuvius type with the height of the somma 2317 m. The volcano contains a base 4 km wide and a summit crater 350 m wide and 220 m deep.

The somma is open to the southwest, along a series of faults which have been the orientation of eruptive activity. Eruptions over the past 300 years have followed a Poisson distribution with a probability of 1-2 eruptions over the next 20 years.

A caldera forming eruption occurred 30,000–40,000 years ago in a major landslide
which covered an area of 500 sq km south of the volcano. Avachinsky is potentially dangerous due to its proximity to large population centres.

Hazards at the volcano include ash plumes, ash falls, lava and pyroclastic flows, hot avalanches and lahars. Eruptions of Avachinsky Volcano pose an aviation hazard, due to its proximity to flight paths, and ash emissions which can reach 10-15 km above sea level and extend for hundreds of kilometers.

Over the past 188,000 years eruptions at Avachinsky Volcano have been either explosive or effusive-explosive. Future explosive eruptions may deposit up to 10 cm of ash 30 km downwind of the volcano.

2001 Eruption
On 5th October, a single explosion ejected ash to less than 1 km above the crater, and small amount of ash fell on the SE flank.

1993-94 Fumarolic Activity
New fumaroles appeared after the 1991 eruption on the summit of Avacha Volcano with maximum-temperature of 473 C. The fumaroles discharged almost pure magmatic gas. The fumaroles are derived from the condensed magmatic gas with a low meteoric water fraction.

1991 Eruption
The 1991 eruption of Avachinsky Volcano was small with lava extrusion into the summit crater. The explosive eruption lasted from 13-30 January. New fumaroles appeared after the 1991 eruption on the summit of Avacha Volcano with maximum-temperature accessible sites of 473 deg C, and they discharged almost pure magmatic gas. The gases may have been caused by the mixing of a methane-rich regional thermal water with magmatic fluid.

1926 Eruption
An eruption of Avachinsky volcano in 1926 produced a small lava flow on the southern slope below the crater.

1894-95 Eruption
The eruption was preceded by an earthquake and produced pyroclastic flows.

1779 Eruption
An eruption of Avachinsky volcano in 1779 was witnessed by Captain Cook's expedition. The eruption of 15-16 June 1779 was one of the largest at the volcano. Ash fell on Cook's ships in Avacha bay.

Avachinsky Volcano Eruptions

2001, 1991, 1945, 1938, 1938, 1927?, 1926, 1910?, 1909, 1901, 1894-95, 1881, 1878, 1855, 1837?, 1828, 1827, 1789?, 1779, 1772, 1737.

Possible eruptions
1550, 1400, 1200, 1100, 900 AD, 700 AD, 400 AD, 100 AD, 1350 BC, 1500 BC, 1700 BC, 2100 BC, 2300 BC, 2500 BC, 2530 BC ± 300, 2650 BC, 2900 BC, 2950 BC, 3200 BC ± 150, 3400 BC, 3500 BC, 3700 BC, 3790 BC ± 100, 4050 BC, 4200 BC, 4250 BC, 4340 BC ± 75, 4400 BC, 4460 BC ± 100, 4550 BC ± 200, 5450 BC, 5500 BC, 5600 BC, 5700 BC, 5980 BC ± 100, 6100 BC.