Apr. 14, 2010

Angel Falls: The World’s Highest Waterfall

Today, when science and technology are deemed highly developed, people  may think that mankind’s explorations have reached every corner of the Earth.  Nevertheless, there are still hidden places where people can hardly set foot.  The Guiana Highlands may be the king of such mysterious places.   Fig. 1. Angel Falls and Its Vicinity Figure 1 depicts Angel Falls and its vicinity as observed by ALOS (“Daichi”) in  December 2009.  The Guiana Highlands are located in northern South America,  extending over Columbia, Venezuela, Guyana, Surinam, French Guiana, and Brazil.  More than 100 isolated table-like mountains (mesas) tower above the Amazon  rainforest, and cover a total area of about 30,000 km2, which is equivalent to the size  of Belgium. The dark green and brown area in the center of the image is one such mesa,  called “tepui,” (“House of the Gods”) in the native tongue. These geological features  are the remains of the hard rock bed of an ancient large plateau that was eroded by rain,  etc., over the course of Earth’s history. The rims of these tepuis are sheer cliffs about  1,000 meters high. Rocks of the Guiana Highlands are very old, formed about 2 billion  years ago. As seen by the many groups of clouds in Figure 1, the rainfall of this area is  also world class. Annual precipitation exceeds 4,000 millimeters.  Because of their ancient  isolation from the forest floor, an entirely unique ecosystem has evolved on the mesa tops,  with various endemic species of plants, insects, and animals, including those still  undiscovered. Sir Arthur Conan Doyle, author of the Sherlock Holmes books, was inspired  by the mysterious Guiana Highlands and novelized The Lost World, a story in which  dinosaurs survived on the highland. Those outstanding figures of table-like mountains make  it easy for us to believe that such imagination could be real. Water falls in abundance from the rim of the mesas to the ground below. Angel Falls is the  highest among them and is located at the table-like mountain called Auyantepui in Venezuela.  With a circumference of 700 km, Auyantepui is the largest table-like mountain in the Guiana  Highland and as large as the Tokyo metropolitan area in Japan. Such a clear image of  Auyantepui and Angel Falls is very rare since this area is cloudy most of the time. Canaima  National Park, which includes Angel Falls,  was added to the World Heritage of UNESCO in 1994. Fig. 2. Enlarged Image of Angel Falls Angel Falls  (kmz, 4.36 MB, High Resolution)  as seen on Google Earth Angel Falls is the highest (978 meters) and most  spectacular waterfall in the world with an uninterrupted descent of 800 meters.  Figure 2 clearly show the white plume of the waterfall. If you listen closely, you  may even hear the roaring sound. However, it has no basin because the height of the  falls is so great that much of the water evaporates or is carried away as a fine mist  before reaching the bottom.   Fig. 3. Three-Dimensional View of Angel Falls (Staring at the image for a long time may cause eye-strain.  A color print is available inPDF.  PDF files for the left and right eyes are also available for stereoscopic viewing.) The table-like mountain and Angel Falls can be enjoyed in 3D if viewed with a blue  glass over  the right eye and a red glass over the left eye. The difference of heights  between the top of the table-like mountain and the valley, and dissipating water during  the fall might also be recognized.  Note that upward is north in Fig. 1 and 2, whereas the right hand side is north in Fig. 3,  a result of  the flight direction of the satellite.