Alao at Tutuila Island, American Samoa

May 11th, 2010

Alao is a populated place on the narrow east coast of Tutuila Island, American Samoa. It is located close to the island’s easternmost point, just to the north of Aunu’u Island. Alao and Tula villages on the east end of Tutuila are the oldest settlements in American Samoa. They face a long, gorgeous surf beach, but be careful of the undertow from waves driven by the prevailing southeast trade winds. The road turns the northwestern point and climbs precipitously over a mountain ridge and down to Onenoa, a picturesque village tucked in a little bay. You’ll have a fine view of the north shore and the Cockscombs as you descend into Onenoa.
See the map of Alao here:

View Larger Map

Tutuila is the largest and the main island of American Samoa. It is the third largest island in the Samoan Islands chain. The island is distinctive in the Central Pacific for its large, natural harbor, Pago Pago Harbor, where Pago Pago, the capital of American Samoa is situated.

The area of the island is 141.81 km² (54.75 sq mi) with a population of 55,876 (2000 census). (These figures include Aunu’u Island, off the southeast coast of Tutuila, which has a land area of 1.517 km² and a population of 476.)

The highest point on Tutuila is Matafao Peak (653 m or 2142 ft).

Politically, the island is divided into two of American Samoa’s primary divisions, the Eastern District and the Western District.

In the early 19th century, Tutuila was called Maouna.

American Samoa en-us-American Samoa.ogg /əˈmɛrɪkən səˈmoʊə/ (help·info) (Samoan: Amerika Sāmoa  or Sāmoa Amelika) is an unincorporated territory of the United States located in the South Pacific Ocean, southeast of the sovereign state of Samoa (formerly known as Western Samoa). The main (largest and most populous) island is Tutuila, with the Manuʻa Islands, Rose Atoll, and Swains Island also included in the territory. American Samoa is part of the Samoan Islands chain, located west of the Cook Islands, north of Tonga, and some 300 miles (500 km) south of Tokelau. To the west are the islands of the Wallis and Futuna group. The 2000 census showed a total population of 57,291.  The total land area is 200.22 km2 (77 sq mi), slightly more than Washington, D.C. American Samoa is the southernmost territory of the United States.

Park on Tutuila Island

March 12th, 2010

The park is on the island of Tutuila – the largest island in American Samoa, home to the capital of Pago Pago (PAHNG-go PAHNG-go. This island exhibits substantial weathering which has left most of the area with no visible craters from previous volcanic activity. The exeption to this is the Leone Peninsula, formed about 70,000 years ago. Across the park many closely spaced streams can be found which deeply erode the volcanic slopes made of basalt. Drowned valleys, coastal flats, and volcanic intrusions such as Rainmaker Mountain, can also be found on the island. Rainmaker Mountain is a volcanic feature known as a trachyte plug. This means that it is a volcanic intrusion made of extrusive igneous rocks having alkali feldspar and minor mafic minerals as the main components and a fine-grained, generally porphyritic texture. At Vaisa Point on the northern coast of the park unit, streams drop into the sea from hanging valleys created when the erosion of the crashing waves cuts down faster than the erosion caused by the streams. In the western area of the park, pillow lavas can be found in Amalau Cove. Pillow lavas are formed by extrusion of basaltic lava from the seafloor that solidifies underwater. Because of the intense action of the waves at the beach in this area, the boulders and chunks of coral have become known as the “singing rocks” because they can be heard moving back and forth with the motion of the water.

In addition to the local geological activity on each of the islands, American Samoa is also active on a much larger scale. To understand this concept, one must first understand the movement of plates across the earth’s surface. American Samoa is located on the Pacific Plate. This plate also contains the islands of Hawaii and many others. An important feature of the island groups on the Pacific Plate is that the ones located over a hotspot are all oriented in a linear fashion. Since the Pacific Plate is moving in a pretty straight path, all island groups over hotspots were formed in a line that matches the direction of plate movement. This shows that the hotspot isn’t moving, but the plate definitely is. The islands on the Pacific Plate grow progressively older as you move from east to west. As it continues its westward trek, the Pacific Plate is making a slow collision with other plates, including the Australian Plate. The collision of these two massive sections of earth causes quite a bit of geologic disruption in the area including earthquakes and volcanoes. Since the two plates cannot occupy the same area on the earth’s surface, something must happen when they collide. Recent surveys suggest what may be happening below. The Tongan Trench is an area along the seafloor between Samoa and Australia where the Pacific Plate is subducted under the Australian Plate. Long cracks along the seafloor between Samoa and the Tongan Trench oriented in an east-west direction seem to be formed by the bending of the seafloor. These cracks in the seafloor make it easier for hot magma from underneath the earth’s crust to erupt as younger lava on top of older islands. Since we already know that the Pacific Plate is gradually being submerged, it is possible to predict that the Samoan Islands will one day be subducted as well. Slowly, the islands are moving closer and closer to the subduction zone, and at some point they too will be sucked under the Australian Plate. Luckily, American Samoa will be around for millions more years for all to enjoy.