Published: January 19th 2011January 10th 2011
So our day begins with a trip to Arecibo Radio Telescope, the largest radio telescope in the world. But before I get to that, I must talk about the terrain of the drive. Now the roads here aren’t what you would expect in the States. These roads are narrow, no guard rails, and follow the contour of the land. Why you ask, because this island is right on the fault line between the North American and Caribbean plate which makes it prone to earthquakes every now and again. This causes a risk in building bridges since the upkeep would cost so much from the risk of the earthquakes and the landslides as well. The Puerto Rican government saw it to be more finically sound to make roads which follow the contours of the land rather that cutting through it. And in a land where the rate of poverty is 54%, I can see why they would rather have winding, twisty, dangerous roads than constant finical up keep of the bridges.
The land had a large degree of Karst topography, which is created when groundwater dissolves sedimentary rock. These unique landscapes, possessing aboveground and underground features, are what made up most of
This is a haystack hill
the southern end of the islands topography.
When rain falls through the atmosphere, it picks up carbon dioxide and forms carbonic acid. This carbonic acid seeps into the bedrock, which in Puerto Rico consists of limestone, and creates slow-moving groundwater, the combination of which erodes the landscape and creates Karst topography. Karst topography includes caves, sinkholes, and mounds (hills of different kinds).
We made it to Arecibo and began our way through. The construction of the Arecibo telescope was initiated in the summer of 1960 and completed in November, 1963, by Professor William E. Gordon and Zachary Sears of Cornell University, who originally intended to use it for the study of Earth's ionosphere. The original design had a very limited use for other potential areas of research, such as planetary science and radio astronomy, which require the ability to point at different positions in the sky and to track those positions for an extended period as Earth rotates. The telescope has undergone significant upgrades. “Initially, when the maximum expected operating frequency was about 500 MHz, the surface consisted of half-inch galvanized wire mesh laid directly on the support cables. In 1974, a high precision surface consisting of thousands of
Another Karst Hill
This Haystack is more defined
individually adjustable aluminum panels replaced the old wire mesh, and the highest usable frequency was raised to about 5000 MHz. A Gregorian reflector system was installed in 1997, incorporating secondary and tertiary reflectors to focus radio waves at a single point. This allowed the installation of a suite of receivers, covering the whole 1–10 GHz range that could be easily moved onto the focal point giving Arecibo a new flexibility. At the same time, a ground screen was installed around the perimeter to block the ground's thermal radiation from reaching the feed antennas, and a more powerful 2400 MHz transmitter was installed” (www.naic.edu). Many scientists from all over the world do their work here and have become a site of world scientific knowledge. The location of the telescope may seem obsolete but back to that Karst topography, the hills and sink holes provided by the erosion and dissolve of the limestone bedrock gave way to an ideal spot to put the telescope to block out other human radio waves, ensuring more precise data.
After our visit to Arecibo, we made our way to Cueva Ventana (Window Cave). This is what I was looking forward to. And let me tell
This is the view of the reflector which catches the radio waves
you how amazing it was. We meet our trail guides on the side of a Texaco gas station and followed them up to the entrance of the cave. I saw stalagmites and stalactites. I saw bats and could see where the formations of new stalagmites were. But what took my breath away was the view, which was like looking through the window to the landscape below. It’s a local cave, meaning to get there, you need to know where you are going or have a local show you.
There are more photos below