The state of Hawaii is composed of 132 islands, reefs and shoals that extend for over 1500 miles across the central North Pacific Ocean from the “Big Island” of Hawaii to midway and Kure Atolls. The eight main islands of Hawaiian Archipelago include Hawaii, Maui, Oahu, Kauai, Molokai, Lanai, Nihau and Kahoolawe (listed in order of size) which extend for only 350 miles at the south-eastern end of the volcanic mountain chain. Hawaii includes some of the earths largest mountains, rising from oceanic depths of greater than 18,000 feet to a height above sea level of nearly 14,000 feet.
Mauna Kea and Mauna Loa on the Big Island are volcanic mountains with a total relief of 32,000 feet. The entire Island of Hawaii, with its five large volcanoes of Kahala, Mauna Kea, Hualalai, Mauna Loa, and kilauea, and Loihi, is less than 450,000 years old. Kauai and Niihau, at five million years, are the oldest of the main Islands (Kauai on line). Kauai, “The Garden Isle,” is 552. 3 square miles and the population is 50,947. It is geologically the most mature of the main Hawaiian Islands with extensive development of broad, lush erosional valleys and coastal features such as coral/algae reefs and sandy beaches.
Waimea Canyon, at over 2500 feet deep, is Hawaiis largest erosional valley. Nearly 50% of Kauais 111 miles of coastline are lined with beautiful beaches, derived mainly from erosion on reef producing coral and algae. Kauai is the fourth largest of the seven major islands in the chain and was built by a massive volcano, of which Mount Waialeale, at 5,148 feet, is the eastern rim. Kauai is located in Polynesia and in the center of the Pacific Ocean. Its 22N of the equator and 158W and is located just below the Tropic of Cancer.
Being one of the most remote spots and earth, 2500 miles west of California, the biology on the Island is very amazing. Kauai has a wide variety of plant, marine, and animal life. Many species are rare and endangered including Hawaiis only freshwater fish, the oopo (Atlas). Kauai has an ideal climate with average temperatures near the coast of 71 in February and March and 79 in August and September. Cooler temperatures in the mountain areas such as Kokee offer a pleasant contrast. The North Shore also averages about 5 to 7 degrees cooler that the other inhabited parts of Kauai.
Rainfall varies widely, with an average day having sunshine on the beaches and showers in the mountains. The West side of the Island has near desert-like conditions, while the summit of Waialeale is the wettest spot in the world, with an average rainfall of almost 500 inches per year. Normally, the rugged, mountainous interior has much more rainfall than the coastal areas where most communities are located. The Maritime Tropical air mass highly influences Kalalau Valley, Kauai. With its warm and humid weather that it brings in we see how the Island of Kauai goes from stable to conditionally unstable.
The convectional lifting of the air masses around the Island of Kauai shows how an air mass passes a maritime source and it causes lifting in the air mass. If the conditions of the Island are unstable then the lifting is sustained and clouds develop. This is why the temperatures and the rainfall vary with certain spots. For example, Average rainfall ranges from 35 inches at poipu Beach to 444 inches at the summit of Waialeale. The general circulation that influences Kalalau Valley is the Northeast trade winds.
The subtropical high and the southeast trade winds affect the valley as well. Mainly the northeast trade winds and the southeast trade winds influence the state of the Hawaiian Islands. The Island of Kauai and Kalalaua Valley are located in the Tropical Rainforest region. The pattern of precipitation and temperature for Kauai between January 1st and December 31st, was between 45 and 70 for temperature in Fahrenheit. The minimum temperature is about 50 degrees. Precipitation ranged from . 40in. in January about . 05-. 10in. n May through September and back up to about . 40in. in November and December, the mean annual precipitation in Kauai is 43. 1 inches. These patterns exist because of the heavy rainfall during January, February, March, November, and December. That shows why the precipitation was higher during those months. The temperature stays pretty level during the year due to the influence of the Maritime Tropical air mass that occurs in this part of the world. Kauai is near the equator, as well, so much of the temperature range is steady (Weather as we know it).
Geomorphology The 132 islands, reefs and shoals of the State of Hawaii extend for over 1500 miles across the North Pacific Ocean. They represent the tops of some of the planets largest mountains. These dots of land are Earths most isolated islands, being some 2400 miles from both the nearest continental land mass, North America, and the islands of Polynesia in the South Pacific. As a result of the processes of selective migration and evolution on these severely isolated islands, the native plant and animal species of Hawaii are found no where else in the world.
These islands also were one of the last places on earth discovered, occupied and modified by humans( Britannica). The Hawaiian Islands are volcanic in origin. Each island is made up of at least one primary volcano, although many islands are composites of more than one. The Big Island, for instance, is constructed of 5 major volcanoes: Kilauea, Mauna Loa, Mauna Kea, Hualalai and Kohala. Mauna Loa is the largest active volcano on Earth. Kilauea is presently one of the most productive volcanoes on Earth (in terms of how much lava it erupts each year).
The primary volcanoes on each of the islands are known as a shield volcanoes. These were produced by the Hawaiian hot spot, which is presently under the Big Island of Hawaii. Shield volcanoes are gently sloping mountains produced from a large number of generally very fluid lava flows ( Kauia, Earth and time). In general, when you move along the island chain from southeast (Hawaii) to northwest, (Kure), the volcanoes become older and older. In fact, even beyond Kure the Hawaiian chain continues as a series of now-submerged former islands known collectively as the Emperor seamounts.
The two primary volcanoes that make up Oahu (where Honolulu is) have not erupted for well over a million years! The age trend of the volcanoes is thought to be due to the way in which the islands are built on the moving sea floor of the North Pacific Ocean: the Pacific Ocean is mostly floored by a single tectonic plate that is moving over the layer in the Earth known as the Asthenosphere. This movement takes it to the northwest compared to the layers below it at a rate of 5 to 10 cm/yr.
As the plate moves over a fixed spot deeper in the Earth where magma (molten lava) forms, a new volcano can punch through this plate and create an island. The Hawaiian Islands are believed to be formed from one such ‘hot spot’. As the plate moves away, the volcano stops erupting and a new one is formed in its place. With time, the volcanoes keep drifting westward and getting older relative to the one active volcano that is over the hot spot. As they age, the crust upon which they sit cools and subsides.
This, combined with erosion of the islands once active volcanism stops, leads to a shrinking of the islands with age and their eventual submergence below the ocean surface( Vink). Importantly, the time over which various active volcanoes on the islands remain active is long, hundreds of thousands of years, so that significant overlap in ages occur on neighboring islands. For instance although Haleakala volcano on Maui is a great distance away from the presently erupting Kilauea, Haleakala last erupted only about 200 years ago( Vink).
Since Kauai is located in the tropical zone on the map we can see that the weather processes that take place are warm, moist and humid most of the year. Since the Hawaiian Islands are close to the equator, we can see that the equatorial weather processes are dominant. The depositional process that take pace in Kauai are mainly coastal. Depositional coasts are generally located along land of gentle reef, where sediments are available from many sources (Geosystems 399). Such is the case with the Hawaiian Islands.
Erosional processes, during storm activity also influence these depositional coasts. The evident barrier spits, beaches, and Barrier Islands can show many of the depositional characteristics. Another describing factor is the coral reefs that are so magically formed underneath and all around the Hawaiian Islands, A coral is a simple marine animal with a small, cyndrical, saclike body. Corals secrete calcium carbonate from the lower part of their bodies, forming a hard external skeleton (Geosystems 404).