Posts Tagged ‘Hawaii’

Hawaii National Park - Halema’uma’u

Tuesday, May 12th, 2009

The last major activity in Halema`uma`u was in 1967- 1968, with shorter activity in 1981. These eruptions deposited ash, cinders and stones in the nearby area, including the region of the southwest rift zone. Some Hawaiians believe lava is the physical representation of the fire goddess Pele, making the volcano summit sacred.

Hawaiians believe Pele migrated to Hawaii from her home in the South Pacific. When she arrived in Hawaii she traveled down the island chain from Kauai to Hawaii stopping at each island testing the ground for a new home. This story does seem to indicate that Hawaiians recognized the fact that the geological ages of the islands are older from Kauai to Hawaii, the youngest island. Pele finally settles on Kilauea where she is found today.

Pele is perhaps the most visible goddess of the all of the gods and goddesses in Hawaiian mythology. Here at Halema`uma`u her presence is felt everywhere. She is the great destroyer and at once the great creator in the tension between rain, land, forest, and sea. Indeed the name Halema`uma`u means “house of the aumau fern”. This fern represents one incarnation of the god Lono also known as Kama`pua`a. In Hawaii, the clouds and storms are associated with Lono. The signs of Lono are thunder, lightening, earthquake, the dark cloud, the rainbow, rain, wind, whirlwinds that sweep the earth, waterspouts, the clustering clouds of heaven, and gushing springs on the mountains. Lono brings the rains and dispenses fertility, is the god of harvest. Here is acknowledgment of the tension between creation and destruction which the ancient Hawaiians were so familiar with and which persists today.

Hawaiians had the idea that the Earth they lived on was the shell of a giant turtle or honu. In fact the Hawaiian word for Earth is “honua”. The profile great volcano Mauna Loa viewed from the view point at Hale`ma`uma`u resembles a large turtle shell. The slopes of Mauna Loa rise gently. It is this gentleness that distinguishes Hawaiian volcanoes from those found elsewhere along the Pacific “ring of fire”. Volcanoes such as Mt. St. Helens and Mt. Rainier in Washington State or Mt. Mayon and Mt. Pinatubo in the Philippines are known as strato-volcanoes or composite volcanoes. They are built from successive powerful explosive events, are cone shaped, and steep sided. In Hawaii the volcanoes are built up from successive lava flow on lava flow giving them their distinctive gentle turtle backed or shield shape. But here at Halema`uma`u is the origin of the great steam or phreatic eruptions of Kilauea.

Two powerful steam, or phreatic eruptions are known to have occurred at Halema`uma`u in historic times; one occurring in 1790 and the last to occur on May 10, 1924. These explosive eruptions occur when groundwater enters the magma system following rapid drainage of magma from the summit reservoir. The magma drains below the water table and the water flows over the magma resulting in massive explosion with towering ash clouds. The 1790 eruption is famous in Hawaiian times. It occurred as the Chief of the Ka`u district, Keaua, was moving his army across the summit of Kilauea to oppose the rising power of Chief Kamehameha. His army was trapped in the explosive rock and choking sand ash. These ash clouds were reported to be visible from the other side of the island at the village of Kawaihae. From these reports the ash column created by this eruption is estimated to have been some thirty thousand feet high. Ash deposits thirty feet thick stretching for twelve miles out from their source are documented. In this tremendous storm over nearly one hundred of Keaua’s Hawaiian warriors were killed. Hawaiians call this event “keonehelelei”, “the falling sands.” Evidence of this can still be seen today southwest of Halema`uma`u, in the “foot prints” area of the Park. Here the footprints of Hawaiian warriors can still be found petrified in the ash. There are two levels of foot prints in the ash, one set from those which were killed and another set from those which came to remove the bodies for burial.

Geologists have found evidence for numerous explosive eruptions at Kilauea Volcano in the more distant past but the most recent was that of May 10, 1924. Explosions from Halema`uma`u began on this date and last for a period of eighteen days. Explosions tossed rocks weighing as much as eight tons as far as 0.6 miles from the crater. Many of these are still visible southwest of Crater Rim Drive. Unlike the hapless Hawaii army caught in the 1790 eruption only one individual was killed in 1924, a Mr. Taylor, who approached too close to the crater during one of its eruptions. Again, as in 1790, an ash column some six thousand feet high rose above Halema`uma`u. On this occasion Thomas Jagger and his crew were able to document the eruption. They found that at the beginning of the eruption Halema’uma’u Crater was an oval pit about 1,740 feet across, with a lava pond about 165 feet below the rim. At the end of the 1924 series of explosive eruptions, Halema’uma’u was about 3,150 feet across and 1,300 feet deep. The other difference from 1790 was that that 1924 eruption was apparently quite the tourist attraction. Old photos show crowds of people viewing the ash column across Kilauea caldera from the Volcano House. These explosive events are not frequent. Perhaps hundreds of years pass between each event. In Jaggar’s day, fifty years before and after, Halema`uma`u was primarily a lava lake sometimes glowing so brightly that that you could read a newspaper out of doors without any additional lighting. This intense glow can also be seen hundreds of miles out to sea and was thought to act as a beacon for early Polynesian navigators. Indeed, Hawaii Island is thought to be the first island early Polynesians arrived at. Today Halema`uma`u is about three thousand feet across, three hundred feet deep, and quiescent. Here it is common to see a large long-tailed white bird flying about. This is the white-tailed tropic bird, known locally as Koa’e or crater bird. It feeds at sea, but nests in the crater wall.

Learn more about Halema’uma’u

Hawaii National Park - Thurston Lava Tube

Thursday, April 2nd, 2009

At the turn of the century, Lorrin Thurston, publisher and owner of the Honolulu Pacific Advertiser, and majority investor in the Volcano House, spent many of his days exploring the area of Kīlauea volcano.  One of his discoveries was a giant lava tube.  Lava tubes are formed when rivers of lava cool and crust over.  The still molten lava in the interior continues to flow down hill.  Eventually the lava drains out of the tube leaving a cave like shell.  Some of these tubes can be up to ten miles long and quite large in the interior.  Some have been measured from twenty to fifty feet from floor to top and twenty to thirty feet wide. They are indicative of the great volume of lava which has passed through them. What is most interesting geologically about the Thurston Lava Tube is where did the lava come from which formed this tube.  The lava tube is above the summits of Kilauea Iki and Kīlauea. The answer to this puzzle is that Thurston lava tube is of great age. It was created well over ten thousand years ago when the summit of Kīlauea was much higher than it is today. Geologists call this ancient Kīlauea, `Ailau (pronounced: “eye-lau”), meaning “to eat much.”  The summit of `Ailau was located where Kīlauea Iki is today and disappeared in a massive summit explosion over ten thousand years ago, leaving behind the only evidence of its existence in the Thurston Lava Tube  

The Thurston Lava Tube is a major attraction along the Crater Rim Drive. Thurston Lava Tube is located in the rain forest ecological zone. The abundant rainfall contributes to the lush growth of the forest canopy trees and the under storey vegetation one sees along the trail to the lava tube.  These forests are most characterized by the presence of large `ōhi`a trees and hapu`u (pronounced: “ha-poo-oo”), or the large tree ferns which dominate the forest here.  These tree sized ferns grow slowly, maybe only one inch per year, so some of the larger tree ferns here are over one hundred years old. The lush growth also attracts abundant native birds such as the `amakihi and `apapane which can be easily heard and seen in this area. Lava tubes have extremely interesting ecology and support rare live forms such as blind crickets and spiders which have adapted to these dark, cave like, structures.  The visit here consists of a short walk down a paved trail as it descends into a pit crater (the sides of which are hard to distinguish because they are covered with vegetation) and then through a short section of the lava tube itself.  The tube has interior lighting so you may be able to observe the drip line and features of the once liquid lava.  Tree roots dangle from the roof and water drip in the cool, dark, environment. Finally, the trail loops back to the starting point. 

Learn more about Hawaii National Park