In the Empty Quarter, there are five types of sand landscapes that look wonderful. Each one was created because of different climatic and location factors. What make Empty Quarter amazing are the types of sand dunes, amount of water, and the ancient city.
The first type is Barchan dunes, these dunes are located in the Northeastern part of the area, and they can reach around 150-200 meters (492.12-656 ft) in height. Also, it often contains moist "sabkha" that interspread among the Barchan dunes (The Empty Quarter). Sabkah is a crusty surface, flat area between a desert and the sea. Also, it contains salt, gypsum, and calcium carbonate. It has bow shape because of its movement with the wind.
Figure 1: From looking at the slipface, we know that the wind blows from right to left. Also, the dune moves with the wind, which mean that dune slowly moves from right to left as well.
The second type is Star Dunes; we believe these types of dunes are unique because of their shapes. Also, they have steep paramedic shapes and steep tops. This type of dunes can reach 200 meters (656 ft) in height; they are located in the Southeast of the Empty Quarter (The Empty Quarter).
Figure 2: As shown, the star dune has its unique shape because of the complex wind directions. the wind is blowing almost from every direction.
The third type is Domal Dunes, this type of dunes are located in the middle of the empty quarter and their height usually around 100 meters (328.08 ft) (The Empty Quarter). Also, they are inter-structured. These dunes do not have steep edge because of the complex wind direction and look like domes. According to National Geographic, this kind of dunes are the rarest (Dune).
Figure 3: this kind of dunes do not have slipface.
The fourth type is Longitudinal Dunes, sometimes called "linear" or "Seif" dune; this dunes spread between the Southwestern and the Northeastern part of the Empty Quarter in a parallel formation. Also, it can get up to 100 meters (238.08 ft) (The Empty Quarter). Complex wind directions create star, domal, and longitudinal dunes.
Figure 4: it shows how the dunes are formed parallel to the wind direction.
The fifth type of landscape is Sand Sheets, this type of landscape looks like a sheet of sand that covers the ground and it includes low hills; this landscape is considered the most flat landscape of the Empty Quarter (The Empty Quarter).
Figure 5: It shows how the flat ground of the desert look like
As everyone knows that the Empty Quarter desert has one of the hardest climates in the world. The climate can reach 61 degrees C. (142 degrees F) and 2% humidity, which is very dry (Wynn, Jeff). Also, the Empty Quarter contains aquifers. From understanding the lakes existence, some water tables are higher than the ground itself, which creates small lakes, thus creating oases. According to McClore’s doctoral thesis at London University about the Empty Quarter, lakes were formed in two separate periods of time. The first lakes were formed 37,000 to 17,000 years ago. And, the second lakes were formed 10,000 to 5,000 years ago (McClure, Harold).
The Empty Quarter got its name because of its emptiness. However, we found it not empty after all. It preserves a whole city under the ground, "Iram of the Pillars" city, which is also named "the Atlantis of the Sand" (Iram Of The Pillars). It is located in the Southwest of the Empty Quarter. We believe that the existent of the city under the sand suggests a second explanation of how the desert was formed in that area. Instead of slow sand transportation, we believe that a massive sand storm "massive Haboob" hit the city all of a sudden and buried the entire city.
Future Prediction:
We believe that after 1,000 years, rock decaying will happen to the surrounding mountains, which will transport more sand from the mountains to the desert. Also, the hight of the mountains might decrease measurably, but the changes will be detected by the naked eye. After 10,000, we believe that the vegetation will extend from Salala (city in Oman, which is located southeastern of the Empty Quarter) to the Empty Quarter covering up to half of the Empty Quarter. Also, the vegetation will grow from Salala toward the Northwest up to the middle of the Empty Quarter. We believe that rock decaying will affect mountains to a degree, that the naked eye will be able to notice the changes. After 1,000,000 years, we believe that the vegetation will cover the Empty Quarter and the water tables will rise, creating more lakes. Also, we predict that mountains near the Red Sea will decay during those years. Chances are that a river will be formed, it could extend from the starting point at Oman, going throw the empty quarter to the Red Sea. The mountains that surround the desert, on the other hand, might become small to medium sized hills because of rock decaying. The Arabian peninsula could move closer to Iran, thus increasing the size of the Red Sea. Some of the sand dunes will become petrified (sand dunes that got solidified), before the time when vegetation covers the entire empty quarter.
Figure 6: This is an example of a Petrified sand dunes from Arches National Park.
References:
"Dune." National Geographic Education. Web. 07 May 2013. <http://education.nationalgeographic.com/education/encyclopedia/dune/?ar_a=1>
"Iram Of The Pillars: The Atlantis Of The Sands." Explorers Journal. N.p., 20 Nov. 2012. Web. 07 May 2013. <http://www.explorers-journal.com/iram-of-the-pillars-the-atlantis-of-the-sands/>.
McClure, Harold.”Late Quaternary Palaeoenvironments of the Rub’ al Khali.” PhD thesis, University of London. 1984. 07 May 2013
"The Empty Quarter." Saudi Geological Survey. Web. 07 May 2013. <http://www.sgs.org.sa/english/earth/pages/emptyquarter.aspx>.
Wynn, Jeff. "The Empty Quarter Expeditions." The Wynn Family Organization.Web. 07 May 2013. <http://www.wynn.org/EmptyQuarter/>.
Figure 1: http://www.schweich.com/imagehtml/dunebarchan.html
Figure 2: http://www.environmentalatlas.ae/geographicInheritance/dunesAndSabkha
Figure 3: http://www.sgs.org.sa/english/earth/pages/emptyquarter.aspx
Figure 4: http://www.handsontheland.org/grsa/resources/curriculum/mid/dunes/photo_files/longitudinal.htm
Figure 5: http://www.sgs.org.sa/english/earth/pages/emptyquarter.aspx
Figure 6: http://members.virtualtourist.com/m/p/m/68cb3/
No comments:
Post a Comment