Rio Chagres Earthcache
Before the present-day isthmus (a narrow strip of land connecting two larger land areas) was created, water covered the area where Panama is today. A significant body of water (referred to as the Central American Seaway) separated the continents of North and South America, allowing the waters of the Pacific and Atlantic Oceans to mix freely. Beneath the surface, two plates of the Earth's crust were slowly colliding, forcing the Pacific Plate to slide under the Caribbean Plate. The pressure and heat caused by this collision led to the formation of underwater volcanoes, some of which grew large enough to form islands as early as 15 million years ago. Meanwhile, movement of the two tectonic plates was also pushing up the sea floor, eventually forcing some areas above sea level. Over time, massive amounts of sediment (sand, soil, and mud) from North and South America filled the gaps between the newly forming islands. Over millions of years, the sediment deposits added to the islands until the gaps were completely filled. By about 3 million years ago, an isthmus had formed between North and South America.
The Chagres River Basin is located in this isthmus. The Chagres River and its tributaries collect up to 200 inches of rain a year. This water flows quickly down the mountainsides and fills a man-made lake called Lake Alajuela. The Madden Dam, which is located on this lake, lets enough water out of the lake to fill the Panama Canal and its locks, and also to generate the electricity needed to operate the canal. The river then continues on below the lake, splitting to flow northwest to the Atlantic and southeast to the Pacific.
There are two requirements to log this Earthcache:
1.) At the mouth of the river, there is a very defined projection of land that Fort San Lorenzo is built on. Describe the rock that makes up this feature. Explain why this rock is exposed.
2.) Upload a picture of yourself with your GPS in hand with the mouth of the river in the background.
3.) You can log this cache straight away after you have emailed your answers to the cache owner, no need to wait for confirmation.
~~~ CONGRATULATIONS!!! ~~~
FTF: Herpers, Canada
STF: mdsearcher, USA
TTF: Team Mumu, USA
