What kind of lava does mauna loa have

Technical Announcements. Employees in the News. Emergency Management. Survey Manual. Rising gradually to more than 4 km 13, ft above sea level, Mauna Loa is the largest active volcano on our planet. Its long submarine flanks descend to the sea floor an additional 5 km 16, ft , and the sea floor in turn is depressed by Mauna Loa's great mass another 8 km 26, ft. This makes the volcano's summit about 17 km 55, ft above its base! Mauna Loa is among Earth's most active volcanoes, having erupted 33 times since its first well-documented historical eruption in It has produced large, voluminous flows of basalt that have reached the ocean eight times since A series of 33 radial vents also extend to the northwest.

Eruptions of Mauna Loa most often will begin in the summit caldera and then later migrate to a rift zone. Mauna Loa has erupted 33 times since — averaging once every five years. Over a longer period of time, the past 3, years, its estimated to have erupted once every six years.

We are currently in the volcano's longest quiet period since written records have been kept, as it has not erupted since Notable Eruptions of Mauna Loa. Last updated: October 29, Contact the Park Mailing Address: P. Mauna Loa is categorized as a shield volcano, with mountain slopes built up by numerous fluid lava flows. The flows are of two main types from the volcano's eruptive summit caldera. Pahoehoe sheets covering the volcano's northwest and southeast flanks are smooth formations from slowly moving lava.

Roughly textured a'a flows are from rapidly moving lava. When it cools the lava forms a rock type called tholeiitic basalt. Lava flowing from Mauna Loa's rift zones are called picritic melts and are composed of olivine-rich basalt known as picrites.

Tholeiites are a type of basalt generated by subduction of the Earth's tectonic plates underneath Mauna Loa. Tholeiitic basalt has a fine-grained intergranular groundmass lacking olivine. The extrusive igneous rocks are melted layers of the Earth's crust formed deep below the surface. The primary components of tholeiitic basalt are plagioclase feldspar, clinopyroxene and iron ore.

The rocks have a low silica content and range in color from black, gray and dark green to reddish brown. Types of Volcanoes and Their Characteristics.