The Creation and Geography of the Galapagos Islands

The Galapagos Islands are located on the Nazca Tectonic Plate.  This plate slowly moves (about 79 mm a year) eastward over the Galapagos Hot spot, which eventually created the islands due to the Nazca and its neighbor plate, the Cocos, being pushed apart.  The easternmost islands are millions of years older than the western islands due to the eastward movement of the Nazca Plate.  Each of the major islands, excluding Isabela, were formed by one volcano erupting. Isabela, the largest island in the Galapagos, was formed when six volcanoes were joined together by lava above sea level.






The Island Isabela and her six volcanos, as well as the Island Fernandina to the west, which has one volcano.





 Due to the volcanic creation of the islands, most of the islands have a conical shape to them.  The mountainous islands were formed by continuous volcanic action that created a build-up of layers of volcanic rock.  Compared to other land masses, the Galapagos islands are young, ranging from five million years to hundreds of thousands of year old, and are still being formed by the hot spot.

The Galapagos' geography is continuously changing.  The easternmost islands are constantly eroding due to the constant bashing of waves on the ancient shorelines.  The westernmost islands are continuously being formed by volcanic eruptions, the most recent being on April 2009 on the island Fernandina. The marks of volcanic eruption are present everywhere on the islands.  Due to their weird way of creation, sharp inclines are visible all over the islands, but mostly on the shorelines.  The lava can form craters, such as Los Gemelos (the twins), but can also form strange patterns and shapes on the ground.



A view from the side of one of the Los Gemelos


Because the islands were formed by lava, they are mostly dry and arid lands.  However, close to the volcanoes on the older islands usually lies a more lush area, where plants can grow.  This is another factor that makes the Galapagos Islands unique.

The ebb and flow of the volcanos' lava has created these unique islands, and has made their geography unlike any other place.

How can the species that live on the Galapagos adapt to either the constantly eroding or constantly growing shorelines?  Why would plants begin to thrive on the older islands near the volcanoes rather than the shorelines?
Why is Isabela so large compared to the other islands? How could it have possibly be formed?


Bibliography:

images:
http://localadventurer.com/los-gemelos-santa-cruz-island-galapagos/
http://www.galapagostourist.org/information/geology.php

information:
http://www.galapagostourist.org/information/geology.php
http://www.galapagos.org/about_galapagos/about-galapagos/history/geologic-history/
http://www.geolsoc.org.uk/Plate-Tectonics/Chap3-Plate-Margins/Convergent/Oceanic-continental