Hawai'i Volcanoes National Park: Earth Spectacular Phenomena's World Capital

Name: Hawai'i Volcanoes National Park (United States of America).
Location: in the state of Hawaii, in the Pacific. Hawaii is composed entirely by volcanic islands.
Area: 217,212 acres.

Hawai'i Volcanoes National Park

According to the Polynesian beliefs, the Hawaiian islands were created by goddess Pele. This goddess of volcanoes managed with formidable skills her magic conjures and while she traveled throughout the Pacific, she was building island by island until she finally decided to live in the Kilauea crater, in the Hawaiian archipelago.

The Hawaiian archipelago is made up of five main islands: Kauai, Oahu, Molokai, Maui and Hawaii, mentioned from west to east. They emerged from the depth of the ocean one by one, in different volcanic eruptions separated by a period of about 1 million years.

The formation of this type of chain of islands is based on the existence of igneous points in the Earth's crust, over which the molten materials of terrestrial magma create convection currents. In a determined moment, the crust yields and the volcanic materials are launched outwards in imposing magma jets which solidify in contact with the marine water. This way, the interior part is covered and protected, maintaining its semi liquid state and favoring other jets of pyroclastic materials.

Boiling Volcanoes

The Hawai'i Volcanoes National Park is located in the southeastern side in Hawaii island. It has in its more than 200,000 acres, some quite irregular edges because of the mountains' orography. So, the western limit is composed of the Mauna Loa volcano, a huge plained dome made up of continuing lava contributions, which reaches an altitude of 13,680 feet above sea level. Under the waters, the volcano connects with the ocean beds, situated 13,674 feet in depth. Overall, this volcanic cone reaches a height of about 32,000 feet, 3,000 feet more than the Everest.

The eastern slope of the Mauna Loa descends, inside the limits of the park, 13,000 feet, passing through the sectors known as Red Hill -due to the color that here gets the lava streams-, Mauna Loa Strip, Kipuka Ki and Kipuka Puaulu. Then, the rocky cone of Kilauea crater raises itself, being the most active volcano on Earth. The shape of the Kilauea reminds to the shape of an inverted plate and is perforated at its peak by a huge hole from which shine two fracture zones. The eruptions of the Kilauea are often limited to the caldera and the two fracture zones, especially to the eastern and Halemaumau sectors. In the last 34 years, there have been more than 50 eruptions, highlighting the ones that took place in 1949 and 1959. The former one had a duration of 5 months, whereas the latter expelled an incredible cast of lava that went down the slope covering more than 1,900 feet, demolishing a camping and surrounding landscapes like the Tree Fern Forest.

The basalt magma which feeds the eruptions comes from the terrestrial mantle, from a minimum depth of 30 miles. According to the geographical data, the magma from these depths that goes upwards is accumulated in an irregular configuration chamber that is 2 and a half miles under the volcano's peak. Later, the lava emerges to the surface and flows to natural depressions, where it's deposited forming burning lakes that take a lot of time to solidify. The depth of these lakes and its dimensions, set the cooling time. For instance, the lake from Alae Crater, formed in 1963 and relatively shallow, kept liquid materials for more than 8 months whereas, on the contrary, the lava lasted 25 years to solidify in Kilauea Iki Crater, a lake created in 1959 of more than 40 miles depth. This lake was formed during a spectacular time lapse, featured by 17 different eruptions in a 36-day period of time. Between one eruption and another, the volcanic activity gave up, and some of the lava escaped from the lake through an open fissure towards one half of the caldera depression. Later on, crust fragments which were formed before fell, allowing to determine a notable heterogeneity in the upper levels of the lake.

The Hawaiian lava is from basalt nature. The basalt is the most frequent stone among those originated from the solidification of the magma expelled towards the Earth surface, the Moon surface, and perhaps the surfaces of other bodies in the Solar System. The basalt lava -rich in calcium, magnesium and iron- crystallizes forming dark rocks, made up mainly of siliceous oxides like plagioclase feldspars, pyroxene and olivine (this one makes up the peridot gem), iron oxides like the magnetite and, in lower proportions, iron oxide (titanium like the ilmenite.)

The cooling of these rocks form the classical stripped casts, sprinkled by irregularities that come from the burst of air bubbles.

From the Forest to the Cold Desert

The wide range of altitudes enclosed by the park, from sea level to more than 18,000 feet in the peak of Mauna Loa, results in different climatological variations that go from humid tropical climate to the alpine desert climate.  The vegetable mantle suffers multiple changes, having been described up to 23 different types of vegetation, from the highly diverse damp tropical jungle in 'Ola'a to the alpine tundra in Mauna Loa, passing through the foggy meadows in Ka'u.

A characteristic element of the vegetation of the park are the kipukas or vegetation islands. The lava casts demolish important parts of the jungle. This process is not permanent, leaving in occasions pieces of land untouched which later on would develop a large amount of vegetation. The ecological importance of the kipukas is very high, as they favor the speciation in the island. The fruit fly is a great example. In the last 700,000 years, more than 700 species of this fly have emerged; for each one of these tiny flies, every kipuka is a world, especially if it's surrounded by a hostile environment which prevents the contact with other species.

The colonization of isolated territories of recent formation is an exciting biological challenge. In the case of the Hawaiian birds, it is believed that the archipelago was reached by 14 different invasive flows, giving as a result a bird life with different origins. The finches, Hawaiian goose or the nene, swamphens, or the falcon came from the American continent, whereas the hummingbirds came from Australia and the Old World flycatchers from Polynesia. The posterior speciation has multiplied by several times the number of original species. Therefore, in the case of birds, the 77 current native species come from just 14 initial species. The process of species diversification is astonishing when talking about the invertebrates: from the 250 pioneer insect species, have emerged 3,722 studied species up to this date, whereas in the treetops there are 215 browsing species coming from a single common ancestor.

Hawaii, besides being an unmatchable biological laboratory, offers a unique chance to watch the bowels of the Earth. From 1912, it exists a geological observatory on the edge of the Kilauea caldera, which has allowed important discoveries to be made in the geological and crystallographic study of the volcanoes. Few places in the world can provide an aesthetic emotion comparable to that of being watching the creative forces of the Earth in action.

The Death of Captain Cook

"Our unfortunate Commander, the last time he was seen distinctly, was standing at the water's edge, and calling out to the boats to cease firing, and to pull in. If it be true, some of those who were present have imagined, that the marines and boat-men had fired without his orders, and that he was desirous of preventing any further bloodshed, it is not improbable, that his humanity, on this occasion, proved fatal to him. For it was remarked, that whilst he faced the natives, none of them had offered him any violence, but that having turned about, to give his orders to the boats, he was stabbed in the back, and fell with his face into the water. On seeing him fall, the islanders set up a great shout, and his body was immediately dragged on shore, and surrounded by the enemy, who snatching the dagger out of each other's hands, shewed a savage eagerness to have a share in his destruction."

Hawaii witnessed the lost of one of the most popular sailors of all time, discoverer, among other places, of the Australian continent: Captain Cook. He died on February 18, 1779, being the above transcribed paragraph one of his diary writings, which had to be finished by Captain King.

Sources: Wikipedia & "The Voyages of Captain James Cook: The Illustrated Accounts of Three Epic Pacific Voyages" by James Cook.

No comments:

Post a Comment