Mauna Loa activity update:
Wednesday, Sep 18, 2013
A small earthquake swarm occurred last week under the volcano. During 5-7 September, HVO detected about 350 small earthquakes up to magnitude 2.4 in a tightly clustered area at about 7 km depth west of the summit caldera. Only about 25 were strong enough to be located (map). ... [more]
Friday, Jul 05, 2013
Very weak unrest in the form of inflation and seismic activity continues at the largest active volcano of our earth, which has not erupted since 1984. However, this activity is not strong enough to justify a raise of the alert level from green "normal" to yellow "unrest". There is currently no sign that Mauna Loa will erupt any time soon. ... [more]
Mauna Loa volcanoMauna Loa is the world's largest and one of its most active volcanoes - a giant shield volcano on the Big Island of Hawai'i.
Background:Mauna Loa, world's largest mountain and volcano, is a archetype of a basaltic shield volcano in its late mature stage of life, and only about 600,000-1,000,000 years old. Although not erupting as frequently as its younger neighbor Kilauea, it is also one of the most active volcanoes of the world. When it erupts, its eruptions are usually huge and produce large rivers of lava that have repeatedly threatened the town of Hilo.
Mauna Loa rises almost 9 km above the sea floor and the weight of the massive mountain has depressed the oceanic crust down by about 8 kilometers, so the whole pile of volcanic rocks produced from Mauna Loa is probably about 8+5+4=17 kilometers! It has eruptions both from its summit, occupied by a large caldera, and its NE and SW rift zones on the flanks. Almost 90% of Mauna Loa's surface is is covered by lavas less than 4000 years old, while about 50% of its surface is covered by lavas no older than about 1500 years old, while about 25% are covered by lava flows younger than about 750 years, i.,e. emplaced after the formation of the Mokuaweoweo summit caldera.