GEOGRAPHY, OCEANOGRAPHY, AND WEATHER
Why is it important to understand geography in relation to the weather?
There are a couple of reasons why geography is an important science for meteorologists to understand. One is that geographical features, such as mountains and coastlines, have an important influence on the weather. The other is that meteorologists interpret data from satellites, radar, and computer projections on various types of maps, and it is important for them to be able to visualize this data in three-dimensional space because the planet is not flat.
Who initially proposed the idea of moving continents?
The idea of the continents moving around our planet was mentioned as early as 1587 by the Flemish map maker (with German origins) Abraham Ortelius (1527-1598) in his work Thesaurus geographicus. In 1620, Francis Bacon (1561-1626) also mentioned the idea, noting the fit of the coastlines on both sides of the Atlantic Ocean. By the 1880s, many other scientists were mentioning the connection. For example, in 1885, Australian geologist Edward Seuss (1831-1914) proposed that the southern continents had once been a huge landmass that he called Gondwanaland.
But it was German scientist Alfred Wegener (1880-1930) who first formally published the idea of continental displacement (or drift) in his 1915 book, The Origins of Continents and Oceans. He believed the continents were once joined together into one supercontinent, a place he named Pangaea (also spelled Pangea, meaning "all land") that was surrounded by a superocean called Panthalassa. He also suggested that the massive continent divided about 200 million years ago, with Laurasia moving to the north and Gondwana (or Gondwanaland) to the south. Wegener based his ideas of continental motion on numerous observations: The continental distribution of fossil ferns called Glossopteris (from studies by Seuss); the discovery of coal in Antarctica by Sir Ernest Henry Shackleton (1874-1922); similar glacial erosion seen in the tropical areas of India, South Africa, and Australia; the apparent fit of the South America and west African continental shorelines; and, although it may only be legend, by watching ice floes drifting on the sea.
Although Wegener is now considered "the man who started a revolution" in geology, his ideas were hotly debated by scientists of his time. Not only was he a meteorologist in a community of geologists, but he could offer no logical mechanism for the movement of the landmasses. It wasn't until the 1960s, long after his tragic death in Greenland (he died at the age of 50 while on a rescue mission), that Wegener was vindicated. By then, scientific measurements, observations, and technology had advanced enough to prove that, indeed, the continents are moving around the planet on giant lithospheric plates. Wegener's theory of continental displacement was replaced by the new field of plate tectonics, which is the basis for modern geology.
So, what is the modern theory of plate tectonics?
The Earth's crust and lithosphere are broken into over a dozen thin, rigid shells, or plates, that move around the planet over the plastic aesthenosphere in the upper mantle. The interaction between these plates is called tectonics, from the Greek tekon for "builder"; plate tectonics describes the deformation of the Earth's surface as these plates collide, pass by, go over, or go under each other. In other words, plate tectonics describes how these plates move, but not why.
Overall, plate tectonics combines Wegener's theory of continental displacement (or drift) and Hess's discovery of seafloor spreading (see below). The theory has truly revolutionized the study of the Earth's crust and deep interior. It allows scientists to study and understand the formation of such features as mountains, volcanoes, ocean basins, mid-ocean ridges, and deep-sea trenches, and to understand earthquakes and volcano formation. It also gives clues as to how the continents and oceans looked in the geologic past, and even how the climate and life forms evolved.