Sunday, February 5, 2012

Earth Plate tectonics

From the origin of earth there may be Several high earth quick and land slide through the land. As a result of this matter there made large land plates of the earth.That means scientific theory that describes the large scale motions of Earth's lithosphere. Tectonic plates are able to move because the Earth's lithosphere has a higher strength and lower density than the underlying asthenosphere. Lateral density variations in the mantle result in convection. Their movement is thought to be driven by a combination of the motion of seafloor away from the spreading ridge (due to variations in topography and density of the crust that result in differences in gravitational forces) and drag, downward suction, at the subduction zones. A different explanation lies in different forces generated by the rotation of the globe and tidal forces of the Sun and the Moon.

The main force that shapes our planet’s surface over long amounts of time is the movement of Earth's outer layer by the process of plate tectonics.This picture shows how the rigid outer layer of the Earth, called the lithosphere, is made of plates which fit together like a jigsaw puzzle. These plates are made of rock, but the rock is, in general, lightweight compared with the denser, fluid layer underneath. This allows the plates to "float" on top of the denser material.Movements deep within the Earth, which carry heat from the hot interior to the cooler surface, cause the plates to move very slowly on the surface, about 2 inches per year. There are several different hypotheses to explain exactly how these motions allow plates to move.Interesting things happen at the edges of plates. Subjection zones form when plates crash into each other, spreading ridges form when plates pull away from each other, and large faults form when plates slide past each other.

Saturday, February 4, 2012

World Maps


Mapping history of the world is unbelievable.  Because it goes very fast of the ancient decades. Many of the ancients and explorers try to make a world map as possible. In many ancient texts Jambudvipu environed by oceans is very detailed described - an ancient continent having a rounded form and stretched in the south to India (or to Tibet which was in this place before India). In its central part there was Meru mount (Sumeru) identified with the world center, or the North pole. Such continent only Hyperborea cold be and only in Paleocene time (when there was no inner sea in its central part yet) or in Eocene time (when Meru mount was in the middle of an inner sea). 
In any event, it was not earlier than 66 million years and not later than 34 million years ago (most likely, not later than 45-40 million years ago)... 
The very detailed description of geography of this continent in the Old Indian literature speaks that there existed then some highly-developed civilisation on it which had excellent cartographers and has managed to save data about this country during subsequent 40 or even 60 million years. 
А. Koltypin " Battles of ancient goods"

The first complete world map drawn by  Ptolemy who travel around the world by finding secrets about the world.
Old maps provide much information about what was known in times past, as well as the philosophy and cultural basis of the map, which were often much different from modern cartography. Maps are one means by which scientists distribute their ideas and pass them on to future generations.Cartography is the art and science of making maps. The oldest known maps are preserved on Babylonian clay tablets from about 2300 B.C. Cartography was considerably advanced in ancient Greece. The concept of a spherical Earth was well known among Greek philosophers by the time of Aristotle (ca. 350 B.C.) and has been accepted by all geographers since.
Greek and Roman cartography reached a culmination with Claudius Ptolemaeus (Ptolemy, about A.D. 85-165). His "world map" depicted the Old World from about 60°N to 30°S latitudes. He wrote a monumental work, Guide to Geography (Geographike hyphygesis), which remained an authorative reference on world geography until the Renaissance.

Maps became increasingly accurate and factual during the 17th, 18th and 19th centuries with the application of scientific methods. Many countries undertook national mapping programs. Nonetheless, much of the world was poorly known until the widespread use of aerial photography following World War I. Modern cartography is based on a combination of ground observations and remote sensing.

Map of the Danish Kingdom, 1629, by Janssonius. A high level of geographic accuracy is demonstrated along with marginal illustrations that enhance the map. Reproduction of original map from the Geodetical Institute of Denmark.
Visit link for More

Geographic information systems (GIS) emerged in the 1970-80s period. GIS represents a major shift in the cartography paradigm. In traditional (paper) cartography, the map was both the database and the display of geographic information. For GIS, the database, analysis, and display are physically and conceptually separate aspects of handling geographic data. Geographic information systems comprise computer hardware, software, digital data, people, organizations, and institutions for collecting, storing, analyzing, and displaying georeferenced information about the Earth (Nyerges 1993)

Current World Map
Individual maps of countries tell the same story, with London, Sydney, Paris and Dublin all bulging out as the most populated areas. Interestingly, a look at the U.S. map shows a more even distribution of big-name cities, with Chicago taking a prominent place alongside New York and Los Angles. At present it is very easy to take a world map with the development of satellite technology. For a example Google earth service provide wide services of all education, Research,Security and transportation sectors.

The Earth

Apollo image of  the Earth
Important Basic information about the Earth


Age of the Earth: 4.5 to 4.6 billion years
Revolution around Sun: 365.2425 days
Average Distance from the Earth to the Sun: 93,020,000 miles    (149,669,180 km)
Average Distance from the Earth to the Moon: 238,857 miles (384,403.1 km)
Earth's Circumference at the Equator: 24,901.55 miles (40,075.16 km)
Earth's Circumference Between the North and South Poles: 24,859.82 miles (40,008 km)
Earth's Diameter at the Equator: 7,926.28 miles (12,756.1 km)

  1. Earth's Diameter at the Poles: 7,899.80 miles (12,713.5 km)
  2. Water vs. Land: 70.8% Water, 29.2% Land
  3. Atmosphere Content: 77% nitrogen, 21% oxygen, and traces of argon, carbon dioxide and water
  4. Chemical Composition of the Earth: 34.6% Iron, 29.5% Oxygen, 15.2% Silicon, 12.7% Magnesium, 2.4% Nickel, 1.9% Sulfur, and 0.05% Titanium
  5. Rotation on Axis: 23 hours and 56 minutes and 04.09053 seconds. But, it takes an additional four minutes for the earth to revolve to the same position as the day before relative to the sun (i.e. 24 hours).
  6. Highest Elevation on Earth - Mt. Everest, Asia: 29,035 feet (8850 m)
  7. Tallest Mountain on Earth from Base to Peak - Mauna Kea, Hawaii: 33,480 feet (rising to 13,796 feet above sea level) (10204 m; 4205 m)
  8. Point Farthest From the Center of the Earth - The peak of the volcano Chimborazo in Ecuador at 20,561 feet (6267 m) is farthest from the center of the earth due to its location near the equator and the oblations of the Earth.
  9. Lowest Elevation on Land - Dead Sea: 1369 feet below sea level (417.27 m)
  10. Deepest Point in the Ocean - Challenger Deep, Mariana Trench, Western Pacific Ocean: 35,840 feet (10924 m)
  11. Highest Temperature Recorded: 135.8°F - Al Aziziyah, Libya, September 13, 1922 (57.7°C)
  12. Lowest Temperature Recorded: -128.5°F - Vostok, Antarctica, July 21, 1983 (-89.2°C)