Mauna Loa

Mauna Loa is an active volcano in the Hawaiian Islands which forms the core of the island of Hawaii. It is the earth's largest volcano and is actually the exposed peak of an enormous volcanic seamount that was once submerged. As such it is also the Earth's tallest mountain (17 km or 56,000 ft) as measured from its ocean floor base.

The altitude and location of Mauna Loa have made it an important location for atmospheric and other scientific observations. The Mauna Loa Solar Observatory has long been prominent in observations of the Sun.

Eruption in 1840

It was in a state of repose up to 1840, when it burst forth with great fury, and it has continued more or less in a state of activity ever since. There has been a grand eruption very lately, said by the natives to have been the greatest of any on record.

Recent eruption -- Great jet and torrent of lava

A new crater opened near the top, at a height of about ten thousand feet, and for three days a flood of lava poured down the north- eastern slope. After a pause of about thirty-six hours, there was opened on the eastern slope, about half way down the mountain, another crater, whence there rose an immense jet of liquid lava, which attained a height of about a thousand feet, and had a diameter of about a hundred feet. This jet was sustained for twenty days and nights; but during that time its height varied from the extreme limit of a thousand, down to about a hundred feet. The play of this fiery fountain was accompanied by explosions so loud as to be heard at the distance of forty miles. Nothing could surpass the awful grandeur of this jet, which was at a white heat when it issued from its source, but, cooling as it ascended into the air, it became of a bright blood red, which, as the liquid fell, deepened into crimson.

Burning of the forests

In a few days there was raised around this crater a cone of about three hundred feet in height, composed of the looser materials thrown out along with the lava. This cone continued to glow with intense heat, throwing out occasional flashes. The base of this cone eventually acquired a circumference of about a mile. But the fountain itself formed a river of glowing lava, which rushed and bounded with the speed of a torrent down the sides of the mountain, filling up ravines and dashing over precipices, until it reached the forests at the foot of the volcano. These burst into flames at the approach of the fiery torrent, sending up volumes of smoke and steam high into the air. The light from the burning forests and the lava together was so intense as to turn night into day, and was seen by mariners at a distance of nearly two hundred miles.

Great whirlwinds -- Underground explosions

During the day the air throughout a vast extent was filled with a murky haze, through which the sun showed only a pallid glimmer. Smoke, steam, ashes, and cinders were tossed into the air and whirled about by fierce winds--sometimes spreading out like a fan, but every moment changing both their form and colour. The stream of lava from the fountain flowed to a distance of about thirty-five miles. The scene was altogether terrific--the fierce red glare of the lava--the flames from the burning trees--the great volumes of smoke and steam--the loud underground explosions and thunderings,-- all combined to overpower the senses, and fill the mind with indescribable awe.

Other volcanoes in the Pacific

A remarkable volcanic chain runs along the northern and western margins of the Pacific Ocean. It embraces the Aleutian Islands, the peninsula of Kamtschatka, the Kurile, the Japanese, and the Philippine Islands. The most interesting are the volcanoes of Kamtschatka, in which there is an oft-renewed struggle between opposing forces--the snow and glaciers predominating for a while, to be in their turn overpowered by torrents of liquid fire.

External Links

• Mauna Loa Earth's Largest Volcano (http://wwwhvo.wr.usgs.gov/maunaloa/)
• Mauna Loa Volcano (http://www.soest.hawaii.edu/GG/HCV/maunaloa) (USGS)
• Welcome to the Mauna Loa Observatory's web site! (http://www.mlo.noaa.gov/) (NOAA) Links to live cameras and data.
• Mauna Loa Solar Observatory (http://mlso.hao.ucar.edu/cgi-bin/mlso_homepage.cgi)
• Space radar image of Mauna Loa, Hawaii (http://visibleearth.nasa.gov/cgi-bin/viewrecord?1809)
• Lo`ihi (http://www.soest.hawaii.edu/GG/HCV/loihi) seamount is possibly in the process of emerging as a new island.
• Mauna Loa Wilderness (http://www.nps.gov/havo/back_mauna_loa.htm) (National Park Service)