Long Island Volcano | John Seach


Madang Province, Papua New Guinea

5.358S, 147.12E
summit elevation 1280 m
complex volcano

Long Island is located 136 km east of Madang, in the Vitiaz Strait.

The island is 30 km long and 21 km wide. A large part of the interior is occupied by a crater lake. Lake Wisdom is 12 km long and 10 km wide, located at an altitude of 150 m. The active crater is located 3 km from the southern shore of Lake Wisdom.

In November 2007 a magnitude 6.7 earthquake hit 54 km south of the volcano. Long Island activity includes Strombolian and underwater eruptions. Rainfall on Long Island is 2800 mm per year.

2010 Earthquake
A magnitude 5.1 earthquake hit 16 km SE of Long Island on 7th February 2010.

1993 Eruptions
Eruptions began at Long Island in early November 1993. The lake water changed colour from blue-green to orange-brown. The eruption site was north of Motmot Island in the centre of Lake Wisdom.

1973 Eruptions
Eruption occurred in April and May 1968. In October a crater glow was visible from passing ships.

1968 Eruptions
Eruptions occurred at Long Island in March 1968 at the shore of the 1953-55 island. An ash cone formed in a few days and by November 1969 the crater was completely formed with a crater lake.

1953-54 Eruptions
Surtseyan eruptions occurred at a location 4 km from the south shore of Lake wisdom in May 1953. Eruptions continued until January 1954. The eruptions produced Motmot Island which consisted of two craters joined by a ridge.

Great Eruption of 1660
A large caldera-forming eruption occurred at Long Island in 1660, which erupted 30 cubic km of material. The VEI of the eruption was estimated at 6. The eruption was the third largest in the world in the past 2000 years. Local legends in New Guinea talk of the "Time of Darkness". Tephra covered 87,000 sq km of the New Guinea highlands, to a depth of 1.5 cm. Ash deposits on Long Island were 30 m deep.

Long Island Volcano Eruptions

1993, 1976, 1973-74, 1968, 1961?, 1955, 1953-54, 1943, 1938, 1933, 1660.