Galapagos Spreading Center

Hawaiian Islands The Hawaiian Islands, once known as the Sandwich Islands, form an archipelago of nineteen islands and atolls.

The eight main Hawaiian islands (also known as the Hawaiian Windward Islands) are listed here from south to north. All except Kahoʻolawe are inhabited.  Hawaii (also known as the Big Island)  Maui  Kaho’olawe (uninhabited; temporary residential facilities)  Lāna’i  Moloka’i  O’ahu  Kaua’i  Ni’ihau

Hawaii (the Big Island) is the largest and youngest island in the chain, built from five different volcanoes. Mauna Loa, comprising over half of the Big Island, is the largest shield volcano on the planet.

On Sunday, October 15, 2006 at 7:07 am local time, there was an earthquake with a magnitude of 6.7, off the northwest coast of the island of Hawaii, near the Kona / Waikoloa area of the big island in Hawaii. The initial earthquake was followed approximately five minutes later by a magnitude 5.7 aftershock. Minor-to-moderate structural damage was reported on most of the big island, with effects felt as far away as Honolulu, O'ahu, nearly 150 miles from the epicenter, including power outages which lasted for several hours.

Pacific Ring of Fire The Pacific Ring of Fire is a zone of frequent earthquakes and volcanic eruptions encircling the basin of the Pacific Ocean. In a 40,000 km horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, island arcs, and volcanic mountain ranges and/or plate movements. It is sometimes called the circum-Pacific belt or the circum-Pacific seismic belt.

90% of the world's earthquakes and 81% of the world's largest earthquakes occur along the Ring of Fire. The eastern section of the ring is the result of the Nazca Plate and the Cocos Plate being subducted beneath the westward moving South American Plate. A portion of the Pacific Plate along with the small Juan de Fuca Plate are being subducted beneath the North American Plate. Along the northern portion the northwestward moving Pacific plate is being subducted beneath the Aleutian Islands arc. Further west the Pacific plate is being subducted along the Kamchatka—Kurile Islands arcs on south past Japan. The southern portion is more complex with a number of smaller tectonic plates in collision with the Pacific plate from the Mariana Islands, the Philippines, Bougainville, Tonga, and New Zealand.

San Andreas Fault A geological fault that runs a length of roughly 800 miles (1300 kilometres) through western and southern California in the United States. The fault, a right-lateral strike-slip fault, marks a transform boundary between the Pacific Plate and the North American Plate.

A recent study has demonstrated that the San Andreas fault has been stressed to a level sufficient for an earthquake of magnitude 7.0 or greater. Although the San Andreas Fault has experienced massive earthquakes in 1857 at its central section and in 1906 at its northern segment (the great San Francisco earthquake), the southern section of the fault has not seen a similar rupture in at least 300 years. This predicted earthquake could be as close as tomorrow or as far off as a decade or more.

Tethys Sea The Tethys Ocean was a Mesozoic era ocean that existed between the continents of Gondwana and Laurasia before the opening of the Indian Ocean. In 1893, using fossil records from the Alps and Africa, Eduard Suess proposed the theory that a shallow inland sea had once existed between Laurasia and Gondwana. He named it the 'Tethys Sea' after the Greek sea goddess Tethys. The theory of plate tectonics later disproved or overrode many parts of Suess's theory, even determining the existence of an earlier body of water called the Tethys Ocean. However, Suess's overall concept was still relatively accurate and remarkably imaginative for its day, so he generally is credited with the discovery of both the Tethys Sea and the Tethys Ocean.

African Rift Zone The Great Rift Valley is a vast geographical and geological feature, approximately 6,000 km in length, which runs from northern Syria in Southwest Asia to central Mozambique in East Africa. The valley varies in width from thirty to one hundred kilometers, and in depth from a few hundred to several thousand meters.

The volcanic activity at this site and unusual concentration of hotspots has produced the volcanic mountains Mount Kilimanjaro, Mount Kenya, Mount Karisimbi, Mount Nyiragongo, Mount Meru and Mount Elgon as well as the Crater Highlands in Tanzania. The Ol Doinyo Lengai volcano remains active, and is currently the only natrocarbonatite volcano in the world.

Aleutian Islands A chain of more than 300 small volcanic islands forming an island arc in the Northern Pacific Ocean, occupying an area of 6,821 sq mi (17,666 km²) and extending about 1,200 mi (1,900 km) westward from the Alaska Peninsula toward the Kamchatka Peninsula. The islands, with their 57 volcanoes, are in the northern part of the Pacific Ring of Fire, near Alaska. All these island arcs are at the edge of the Pacific Plate and experience a lot of seismic activity, but are still habitable; the Aleutians lie between the Pacific and North American tectonic plates. Sea Salinity  Baltic – 1 part per thousand in the north; 6-8 ppt in the center  Mediterranean – 35 ppt  Aral – 45g/L  Dead – 300 ppt  Red – 40 ppt