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Alright this is my final research summary... enjoy. So you know some of it repeats itself from summary 1. This is of 10/31/04.
SUMMARY 2
Climate: Although the Galapagos lies upon the equator, surprisingly, the temperature ranges are mild. The temperatures average around the 80 degrees Fahrenheit. On average, the warmest months are March and April. Then the temperature is around 87 degrees. The coolest the averages reach are 70 degrees in August. Like most tropical areas, the Galapagos has two seasons: the dry and wet seasons. From January to April it is the wet season. The Galapagos usually receives nearly 350 mm of rain during this time. During the dry season, from April to December, the Galapagos receive less than 75 mm of rain on average (Slater). However, mist usually forms further inland, allowing precipitation to reach the plants and fauna that lie away from the ocean. The reason why the Galapagos receives lower temperatures than expected from a tropical climate is because to the ocean currents that constantly bathe the island. The Humboldt (Peruvian) current typically moves up the western coast of South America, bringing cool, dry air to the Galapagos Islands (“Weather and the Galapagos Islands”). However, every few years, a weather anomaly known as El Nino occurs. This occurs when the Humboldt Current shifts, so the dry season does not arrive. Warm seas continue to bathe the island dumping water and tropical temperatures on the island. Water temperatures can jump up 2 to 4 degrees Centigrade, or 4 to 8 degrees Fahrenheit. Meanwhile, air temperatures also jump by 2 degree Centigrade, or 4 degrees Fahrenheit. Also the rainfall actually can increase over 2000 mm (Glantz) from the average rainfall. This wreaks havoc upon the ecosystem. Marine animals, such as the famous marine iguanas and flightless cormorants die off in huge numbers. For example 45% of the population of cormorant died in the 1997 to 1998 El Nino event. (Glantz) Diseases that affect the digestion systems break out in human populations. Waterborne diseases such as malaria, cholera, and dengue erupted amongst the human populations. Fish die off and ageless coral become bleached by the higher ocean temperatures. Scientists still have trouble accurately predicting the strength and timing of El Nino events. Due to the complexities of the climate surrounding the archipelago, the Galapagos' climate can be seen as a unique system. The uniqueness is also represented by the diversity of the range of organisms that coexist with one another.
Geography: The Galapagos archipelago is a perfect example of a chain island system. This archipelago is millions of years old. The volcanic activity of the Galapagos is due to the sublimation of the Nazca plate under the South American continental plate. In the Nazca crust has a crack in it that allows magma to rise up, forming the volcanoes we see in the Galapagos. As this "hot spot" moves, more islands will grow. Isabela, the newest island still has two active volcanoes craters. Mount Azul, on the island Isabela, recently erupted. There are two predominate "aa" and "panhoehoe" (both are words of Hawaiian origin). The aa lava flows are sharper and stiffer than the panhoehoe. As the flow moves off, the top of the aa hardens and insulates the layer beneath it. The top layer is pulled off to the sides and crumples, forming jagged regions of rock. The majority of volcanoes there are shield volcanoes that still erupt on a regular basis. There have been hundreds of recorded eruptions over the last hundred years. The magma is of basaltic lava origin. Evidence of older islands have been discovered between San Cristobal and the mainland. The volcanism of the island creates many different geological features. For examples, "lava tubes" are created when the upper layer of lava hardens, and the lower layer flows out, leaving an empty tube. These tubes are exposed when sinkholes occur, creating massive lava caves and pits. (Rothman)
-Santa Cruz, a.k.a. Indefatigable Island. It lies 600 miles west of Ecuador and has an area of 389 square miles. The central volcano rises 2300 feet. In the 1982 census, it recorded a population of 2404 people. The Charles Darwin Research Station is located there near the Academy Bay. The island is surrounded by the Galapagos Marine Resource Reserve. Baltra, which lies off the northern edge of Santa Cruz was a former U.S. airbase. It is 8 square miles and used to be attached to Santa Cruz, however, due to volcanic and fault activity, it is now separated. However, the Ecuadorian military has created a base on the island, which also holds the airport that allows visitors to fly to the island. A bridge (that was destroyed by an El Nino event, but rebuilt after) connects Baltra to Santa Cruz. (Enyclopedia Britannica)
Works Cited
Glantz, Michael H. Currents of Change:Impacts of El Nino and La Nina on Climate and Society 2nd Ed. Cambridge University Press. Cambridge, United Kingdom. 2001.
Enyclopedia Britannica (2001). Galapagos Islands [CD-ROM].
Slater Robin. “Galapagos Climate” [WWW Document] URL
<http://galapagos-islands-trail-maps.4t.com/galapagos-islands-climate.html>
(visited 2004, October 1)
“Weather and the Galapagos Islands” [WWW Document] URL
<http://www.pbs.org/safarchive/5_cool/galapagos/g24_weather.html> (visited 2004, October 3)
Rothman, Robert Ph.D. (2002, September 1) URL “Natural History of the Galapagos” <http://www.rit.edu/~rhrsbi/GalapagosPages/Galapagos.html> (visited 2004, October 6)
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