Geography as Spatial Analysis Identifying and Analyzing Spatial

Geography as Spatial Analysis Identifying and Analyzing Spatial Patterns: Example #2

The Theory of Continental Drift and Plate Tectonics How two scientists whose ideas were first dismissed as nuts were eventually proven right.

Scientist #1: An American Geologist, Frank Bursley Taylor u Taylor noticed that the coastlines of eastern South America and West Africa seemed to fit together. u In 1908, he proposed as an explanation a theory of “continental drift”: the idea that the continents had once been joined together but had split and moved apart.

u u He also proposed that many mountain chains had resulted from the collisions between the continents. Since Taylor was an amateur geologist and had no explanation for how the continents moved, he was dismissed by established geologists as a crackpot and a dreamer.

Scientist #2: A German Meteorologist, Alfred Wegener u Wegener was trying to solve a number of puzzles: – How could there be identical fossils of ancient land animals on continents separated by large oceans? u For example, mesosaurus, a 2 foot long 270 million year old fossil of a reptile was found in Brazil, Arizona, and South Africa. – Why were marsupials (animals with pouches) found both in South America and Australia when these continents are divided by the Pacific Ocean?

– Why were there coal deposits along the Arctic Circle north of Norway when almost no plants can grow there and coal consists of fossilized plants? – Why were there identical snails in New England Scandinavia? – Why were there identical fossils of an early form of horse (Hipparion) found in Florida and France when they are divided by thousands of miles of ocean?

In 1912, Wegener Wrote The Origins of the Continents and the Oceans u In his book, he proposed the existence of an ancient supercontinent which he called Pangaea (“all lands”). He argued that this continent later split into the five existing continents.

Wegener’s Idea of a Super Continent Pangaea: c. 225 Million years ago

u Since Wegener was a meteorologist and he had no explanation as to how or why the continents moved he was also dismissed as a crackpot. u Alternative answers to the puzzles consisted mainly of theorized early land bridges connecting the continents. – But there is no geological evidence that such land bridges ever existed!

u In 1930, Wegener disappeared during a research trip to Greenland. His body was later found frozen in a snowdrift.

Sir Arthur Holmes to the Rescue u In 1944, a British geologist, Arthur Holmes presented a theory (later called Plate Tectonics) that explained how continents could move. – He suggested that the earth’s surface consists of many disconnected plates floating on a molten base and in constant motion. u Plate Tectonics is debated for the next 20 years before it gains general acceptance among geologists.

–A key piece of evidence was a map of volcanic and earthquake activity on a world scale.

World Map of Volcanic and Earthquake Activity

The map clearly showed that nearly all volcanoes and earthquakes occurred along certain lines: along the plate boundaries as theory predicted.

The borders of the 12 large plates are defined by volcanic and earthquake activity

u Today most geography and geology texts present “Plate Tectonics” as the accepted explanation for the creation of continents, mountain systems, and ocean troughs, for volcanic and earthquake activity and for the past, present, and future locations of the continents. u Taylor and Wegener, who were regarded as “crackpots” in their own time are now admired as pioneering geologists.

Japan and the 70 Year Rule: What Happens if You Live Near the Edge of a Plate? u Japan is located at the intersection of three convergent plates: The Pacific, The Eurasian, and The Philippine.

u Since 1633, Japan has had a major earthquake roughly every 70 years: 1633 1703 1782 1853

In 1923, The Kanto Earthquake killed 143, 000 people. Tokyo Bay emptied out and then a tsunami swept back in and flooded the city. u In 1995 the Kobe or Great Hanshin Earthquake hit the city of Kobe in southern Japan. 6400 people were killed, 300, 000 buildings were destroyed, and damages totaled $200 Billion. u

u The Japanese government has spent over $1. 3 billion on research into earthquake prediction with no practical results so far. u One day of a false alarm in Tokyo would cost $7 billion.