The Island of Hawaiʻi, also called the Big Island or Hawaiʻi Island (pronounced /həˈwaɪ.i/ in English and [həˈwɐiʔi] or [həˈvɐiʔi] in Hawaiian), is a volcanic island (the eastern-most in the Hawaiian islands chain) in the North Pacific Ocean. With an area of 4,028 square miles (10,432 km²), it is larger than all of the other Hawaiian Islands combined and is the largest island in the United States. The Island of Hawaiʻi is administered as the County of Hawaiʻi within the state of Hawaii. The county seat is Hilo. Traditionally, Hawaiʻi is known as the "Big Island" to reduce confusion between Hawaiʻi Island eology and geography
In greatest dimension, the island is 93 miles (150 km) across and has a land area of 4,028 square miles (10,430 km2)[1] comprising 62% of the Hawaiian Islands' land area. Measured from its sea floor base to its peak, Mauna Kea is the world's tallest mountain, taller than Mount Everest.[2]
[edit]Volcanism
The five shield volcanoes
The Island of Hawaiʻi is built from five separate shield volcanoes that erupted somewhat sequentially, one overlapping the other. These are (from oldest to youngest):
Kohala—extinct
Mauna Kea—dormant
Hualālai—active but not currently erupting
Mauna Loa—active, partly within Hawaiʻi Volcanoes National Park
Kīlauea—active: an eruption began in 1983 and as of 2010 has grown in size; part of Hawaiʻi Volcanoes National Park
Geological evidence from exposures of old surfaces on the south and west flanks of Mauna Loa led to the proposal that two ancient volcanic shields (named Ninole and Kulani) were all but buried by the younger Mauna Loa.[3] Geologists now consider these "outcrops" to be part of the earlier building of Mauna Loa.
Because Mauna Loa and Kīlauea are active volcanoes, the island of Hawaiʻi is still growing. Between January 1983 and September 2002, lava flows added 543 acres (220 ha) to the island. Kīlauea destroyed several towns: Kapoho (1960), Kalapana (1990), and Kaimū (1990). In 1987 lava filled in Queen's Bath, a large, L-shaped, freshwater pool in the Kalapana area.
Steam plume as Kīlauea red lava enters the ocean at three Waikupanaha and one Ki lava ocean entries. Some surface lava is seen too. The image was taken 04/16/08.
Hawaiʻi is the southernmost island in the Hawaiian archipelago, and contains the southernmost point in the United States, (Ka Lae). The nearest landfall to the south would be in the Line Islands. To the north is the island of Maui, whose Haleakalā volcano is visible across the Alenuihāhā Channel.
Eighteen miles (29 km) off Hawaiʻi Island's southeast coast is the undersea volcano known as Lōʻihi. Lōʻihi is an erupting seamount that lies 3,200 feet (980 m) below the ocean surface. Continued volcanic activity from Lōʻihi will likely cause the volcano to breach sea level and attach at the surface to Kīlauea, adding even more land to Hawaiʻi. This event is presently expected in some tens of thousands of years.
[edit]The Great Crack
The Great Crack is an 8-mile (13 km) long, 60 feet (18 m) wide and 60 feet (18 m) deep fissure in the island, in the district of Kaʻū. The Great Crack is actually the
"result of crustal dilation from magmatic intrusions into the southwest rift zone and not from the seaward movement of the south flank. There is no evidence that the Great Crack is getting bigger at this time or that the island is tearing apart along this seam."[4] Furthermore, neither the 1868 nor the 1975 earthquakes caused measurable change in The Great Crack.[4]
Rifts like the Great Crack are often the sites of volcanic eruptions, and in 1823 lava welled out of the lower 10 kilometers (6 mi) of the Great Crack.[4]
Lava enters the Pacific at Hawaii Volcanoes National Park in April of 2005, increasing the size of the island.
One can find trails, rock walls, and archaeological sites from as old as the 12th century around the Great Crack. Much of these finds are on the park side of the fence. About 1,951 acres (7.90 km2) of private land beyond the fence were purchased during the Bill Clinton administration specifically to protect the various artifacts in this area as well as to protect the habitat of the turtles.
Punalu'u Black Sand Beach Park
[edit]The Hilina Slump
Main article: Hilina Slump
The Hilina Slump is a 4,760 cubic miles (19,800 km3) chunk of the south slope of the Kīlauea volcano which is slipping away from the island. Between 1990 and 1993, Global Positioning System measurements showed a southward displacement up to approximately 10 centimeters per year.[5] Undersea measurements show that a "bench" has formed a buttress and that
"this buttress may tend to reduce the likelihood of future catastrophic detachment."[6][7]
[edit]Earthquakes and Tsunamis
On April 2, 1868, an earthquake with a magnitude estimated between 7.25 and 7.75 on the Richter scale rocked the southeast coast of Hawaiʻi. It triggered a landslide on Mauna Loa, five miles (8 km) north of Pahala, killing 31 people. A tsunami claimed 46 additional lives. The villages of Punaluʻu, Nīnole, Kawaʻa, Honuapo|Honuʻapo, and Keauhou Landing were severely damaged. According to one account, the tsunami
"rolled in over the tops of the coconut trees, probably 60 feet (18 m) high ... inland a distance of a quarter of a mile in some places, taking out to sea when it returned, houses, men, women, and almost everything movable."[8]
On November 29, 1975, a 37-mile (60 km) wide section of the Hilina Slump dropped 11.5 feet (3.5 m) and slid 26 feet (7.9 m) toward the ocean. This movement caused a 7.2 magnitude earthquake and a 48 feet (10 m) high tsunami. Oceanfront properties were washed off their foundations in Punaluʻu. Two deaths were reported at Halapē, and 19 others were injured.
The island suffered tsunami damage from earthquakes in Chile in 1946 and Alaska on 27 March 1964. Downtown Hilo was severely damaged in both, with many lives lost. Just north of Hilo, Laupāhoehoe lost 16 school children and 5 teachers in the 1946 tsunami.
[edit]Demographics
As of 2008, the island had a resident population of 175,784.[9] As of 2000,[10] there were 148,677 people, 52,985 households, and 36,877 families residing in the county. The population density was 14/km² (37/mi²). There were 62,674 housing units at an average density of 6/km² (16/mi²). The racial makeup of the county was 31.55% White, 0.47% African American, 0.45% Kanaka Maoli, 26.70% Asian, 11.25% Pacific Islander, 1.14% from other races, and 28.44% from two or more races. 9.49% of the population were Hispanic or Latino of any race.
There were 52,985 households out of which 32.20% had children under the age of 18 living with them, 50.60% were married couples living together, 13.20% had a woman whose husband did not live with her, and 30.40% were non-families. 23.10% of all households were made up of individuals and 8.00% had someone living alone who was 65 years of age or older. The average household size was 2.75 and the average family size was 3.24.
In the county the population was spread out with 26.10% under the age of 18, 8.20% from 18 to 24, 26.20% from 25 to 44, 26.00% from 45 to 64, and 13.50% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 100 males. For every 100 females age 18 and over, there were 98 males.
[edit]Economy
Sugarcane was the backbone of Hawaiʻi Island's economy for more than a century (see Sugar plantations in Hawaii). In the mid-twentieth century, sugar plantations began to downsize and by 1996, the last plantation had closed.
Most of Hawaiʻi Island's economy is based on tourism (see Tourism in Hawaii), centered primarily on the leeward (western) coast of the island in the North Kona and South Kohala districts.
However, diversified agriculture is a growing sector of the economy. Major crops include Macadamia nuts, papaya, flowers, tropical and temperate vegetables, and coffee beans. Kona coffee-branded products must be from the district on this island only. The island's reputation for orchids has earned it another nickname of "The Orchid Isle." The island is home to one of the United States' largest cattle ranches: Parker Ranch, on 175,000 acres (708 km2) in Waimea.
Astronomy is another industry, with numerous telescopes on Mauna Kea because the summit atmosphere's clarity is excellent and there is little light pollution.
[edit]Places of interest
Akaka Falls; the second tallest waterfall on the island.
Amy B. H. Greenwell Ethnobotanical Garden houses many endangered endemic plants.
East Hawaiʻi Cultural Center
Hawaiʻi Tropical Botanical Garden
Hawaiʻi Volcanoes National Park; comprising the active volcanoes Kīlauea and Mauna Loa
Huliheʻe Palace; a royal palace in Kailua-Kona
Lehua blossoms (ʻōhiʻa lehua), Hawaiʻi
ʻImiloa Astronomy Center of Hawaiʻi in Hilo
Ka Lae, the southernmost point in the United States
Laupahoehoe Train Museum
Lyman House Memorial Museum in Hilo
Manuka State Wayside Park
Mauna Kea Observatory; Mauna Kea Observatories
Nani Mau Gardens
Onizuka Space Center; museum dedicated to the memory of Challenger astronaut Ellison Onizuka
Pacific Tsunami Museum overlooking Hilo Bay
Pana'ewa Rainforest Zoo in Hilo
Pua Mau Place Arboretum and Botanical Garden
Puʻuhonua o Hōnaunau National Historical Park
Rainbow Falls State Park
Sadie Seymour Botanical Gardens
University of Hawaiʻi at Hilo Botanical Gardens
World Botanical Gardens
Waipiʻo Valley
Wao Kele o Puna
[edit]Maps
National parks, mountains and cities on the island
Topographical map of the island of Hawaii the stateHawaiʻi
الإثنين مايو 17, 2010 4:16 am من طرف 
