Got a question? Ever wondered about something (hopefully vaguely related to geography)? Then ask away here. Every two weeks, Joe Blanton, director of our Research Correspondence divisionthe folks who respond to thousands of queries and comments received by National Geographic each yearwill post answers to three of the most interesting questions received via e-mail. Unfortunately time constraints preclude individual e-mail responses.
Bones on ice ...
Are dinosaur remains in the Arctic and Antarctic best explained by global climate changes or by continental drift or both?
Both. Fossils of dinosaur remains have been found within 400 miles (644 kilometers) of the South Pole and on Alaskas North Slope; both places are currently too cold for dinosaurs to have consistently thrived there. The dinosaurs found in Antarctica lived during the early Jurassic Period, a time when the earths continental land masses were joined together as Pangaea (Greek for all land). Antarcticas position at that time was farther northat around 65 degrees south latitudethan its current location, and its climate was similar to that of todays Pacific Northwest of the United States. The climate at that latitude is much colder now, so global climate changes have occurred. But Antarctica moved on to even colder realms. As the continental plates continued their inexorable shifting and the continents went their separate ways, Antarctica migrated to its present position, essentially squarely over the South Pole. Although dinosaur fossil finds in Antarctica have been in locations of rare rocky outcroppings devoid of ice, our coldest continent doubtless holds many paleontological secrets beneath its miles-thick ice cap.
The dinosaur remains found in Alaska are from the more recent Cretaceous Period. The location of Alaskas northern coast would not have been much different than that of today. But the climate was warmer then. Even so, the polar regions would have been chilly for dinosaurs in winter. And while the constant daylight of summer would have encouraged plant growth, the long winter's night would have forced plant-eaters to hibernate or migrate.
I have just read the interesting article on the Gaza Strip (in the September issue of NATIONAL GEOGRAPHIC) . I was left wondering what physically defines the strip from the surrounding country?
The Gaza Strip, an elongated rectangle of desert on the Mediterranean coast, is not separated from Israel by any natural barrier. At crossing points between the two political entities, barriers have been constructed of concrete and razor wire. In outlying areas, a fence, topped with razor wire, delineates the border.
If you havent seen it already, check out our Web story on Gaza.
Im a Norwegian who is very interested in the USA. I have been reading your magazine and a lot of books for 17 years now, and I love it. I want to make a 3-D map of the USA, about 4 feet wide, with light diodes for the biggest cities and so on. What I need for this is a map with elevation lines, and that is what Im asking about.
Thanks for the warm comments about our country and about NATIONAL GEOGRAPHIC. What you need to complete your map project is a set of topographical maps. The United States Geological Survey produces some of the best topographical maps of the U.S. You can visit their Web site to learn about maps available at http://www.usgs.gov.
Good luck with your project!
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