Your Independent Study Unit will focus on an individual who has made significant geologic and scientific advances in the field of Physical Geography.

You will concentrate on creating an informative view of that individual, their life history, and details of their importance to the course. Your finished ISU assignment will be in a website format, complete with appropriate pictures, diagrams, and of course, maps!.

The following individuals have made valuable contributions to the field of physical geography as it is known today. What is accepted as fact today was not neccessarily so in the past. Your biography will demonstrate how the knowledge of earth sciences has developed over time.

• a Polish astronomer, wrote On the Revolutions of the Heavenly Spheres in 1530
• he showed that the Earth is not fixed at the centre of the universe, but spins around the sun
• this book was banned by the Catholic Church until 1830

• deduced the Earth was round, as the shadow of the Earth on the Moon during eclipses showed that.
• thought that earthquakes might be caused by winds that fanned flames under the ground.
• wrote Meteorologica, about the atmosphere.

• Greek astronomer
• deduced that it wasn't the stars that spun every day, but the Earth
• the Earth also travels once a year in a huge circle around the Sun, explaining why the star pattern changes through the year
• most astronomers of Aristarchus' time did not agree with his theories.

• one problem many ancient astronomers had was to explain why the tracks of spinning concentric spheres (planets) did not match the tracks of the Sun, Moon, and planets.
• Hipparchus, at Alexandria in Egypt, suggested that the Sun, Moon and planets rotate eccentrically, or slightly off centre.

• wrote a book called Geography
• introduced the idea of "epicycles", or circles within circles, to build a machine that seemed to fit the way the heavens moved, while still keeping the Earth at the centre.
• this system was widely accepted up until the time of Copernicus.

• head of great library in Alexandria
• at a time when most people believed the world was flat, he calculated how big the Earth is to within one percent of today's measurements.
• realized that any place in the world can be pinpointed precisely with a basic grid of lines of latitude and longitude, which he invented.
• his work was forgotten over the centuries

• knew that the Earth spins faster at the Equator than at the poles: it must because the poles move no distance in a day, while points along the equator cover 40 000 km.
• if so, he argued, centrifugal force must be greater at the equator than at the poles, making the Earth bulge at the Equator and flatten at the poles.
• this has been confirmed by satellite measurements.

• in 1552, Dutch mapmaker Gerardus Mercator invented a special kind of cylindrical projection.
• although it makes countries near the poles disproportionately big, Mercator's projection was ideally suited for navigation.
• sailors could work out how to steer a steady course by simply drawing a straight line on the map.

• English engineer
• developed the seismograph in 1880

• British seismologist
• in 1906, showed that the Earth had a liquid core, because there was a zone where P waves bent and S waves stopped totally.

• Croatian seismologist
• in 1909, discovered a marked increase in the speed at which waves traveled when 20 km below the Earth's surface
• this suggested that there must be an abrupt change in material here
• this is now known as the "Mohorovicic discontinuity", and it marks the boundary between the Earth's crust and the mantle.

• German seismologist
• in 1914, detected the boundary between the mantle and the core.
• this is now known as the "Gutenberg discontinuity".

• German meteorologist
• was convinced that the continents were not fixed, but had drifted around the Earth's surface and still were.
• he had no idea what made the continents move, and was ridiculed by his colleagues.

• American geophysicist
• discovered that the ocean floor was made of very young volcanic rock
• with colleagues Bruce Heezen and Marie Tharp, made a map of ocean floor
• they discovered a deep canyon running down the middle of the Mid-Atlantic Ridge

• American geologist
• suggested that ocean floors were not permanent but are spreading out rapidly from the mid-ocean ridge
• the two halves of the ocean were being pushed apart by material from the mantle welling up through the central rift and cooling
• this did not increase the size of the earth, as old ocean crust was being pushed under the mantle and destroyed.

• Irish engineer
• drew a detailed map that pinpointed where earthquakes occurred
• he confirmed that they did not occur at random, but were concentrated in narrow zones

• witness to the A.D. 79 eruption of Vesuvius
• wrote a description of the eruption
• today, the term 'Plinian' is used to describe some of the greatest eruptions.

• in 1935, Richter developed a scale to measure the energy released during earthquakes
• he determined that each earthquake had just one magnitude

• German geologist and world traveller
• his studies showed that basalt must have formed volcanically
• his work helped make it clear that volcanoes play an important part in the rock cycle.

• Scottish geologist; Plutonist
• often regarded as father of modern geology
• believed that landforms were created over a long period of time: the wearing down of rocks by weather and water, the accumulation of eroded material as sediments, formation of rock layers that were eventually folded into mountains.

• professor of geology at Yale University
• argued that the Earth was once a red-hot ball of semimolten rock
• mountains were formed by the way the Earth colled as it shrank.

• American geologist
• in 1859, Hall suggested that mountain building began with the steady accumulation of sediments
• as they built up, the Earth's crust gradually bent under their weight.

• British geophysicist
• suggested that mountains weren't hollow (as they were thought of at that time), but made from less dense rock than the the rock of the mantle below
• Airy also argued that the mountains floatedon the Earth's mantle like icebergs in the sea.

• American geologist
• developed the idea first proposed by George Airy, that the Earth's crust is in a permanent state of floating balance, called 'isostasy'
• according to his theory, lighter rocks rise to form continents, and denser rocks sink to form the ocean floor.

• American geologist
• theorized that the Earth's crust was wrinkled into mountains not by continents sinking, but by continents colliding.

• American geologist
• coined the word "orogeny" to describe the process of mountain building.

• Arabian scholar
• in his Book of Minerals", described how rivers eroded valleys and seas laid down sediments.
• ignored by Europeans until the 1600s.

• German geologist; a Neptunist
• insisted that all types of rock originally settled out of water.
• rocks like granite that had no fossils were "primitive" rocks, laid down before life existed on Earth.

• friend of James Hutton
• promoted further ideas of Hutton's: the vastness of geologic time.

• English engineer
• studied rock strata as he surveyed ground for new canals
• saw that each layer of rock contained a range of fossils,and that the same ranges of fossils were visible in different rocks.
• made first geological map in 1815.

• British geologist
• wrote Principles of Geology in 1830
• book examined the entire geological history of the Earth
• book was the standard text for more than a century.

• French anatomist
• studied fossils, and paleontology was born.

• English scientist
• suggested that landscapes were shaped and reshaped by "vicissitudes of change", or cycles of denudation.
• theories ignored for 130 years, until the time of Hutton.

• Swiss naturalist
• examined glaciers and their effect on landscape
• it was through his work that the idea of ice ages became part of scientific knowledge.

• Danish geologist
• realized that all rocks were originally laid down in horizontal beds, even if they had been tilted, twisted or broken later.
• also realized that layers of sediment were laid down one on top of one another, so the youngest is always at the top.

• American geologist
• first to put forward a cycle of normal erosion

• French scientist
• learned that springs gush more when it rains
• realized that, during intense downpours, rainwater not only runs over the ground, but also seeps into the ground before emerging into a spring.

• American engineer
• found that water flows overland only when a storm is so intense that the ground cannot soak up the water fast enough.
• this event is known as "Horton overland flow".

• English meteorologist
• suggested that winds are affected by the rotation of the Earth.
• spinning of the Earth creates winds that swing to the west.

• French physicist
• showed that anything moving across a spinning surface follows a curved path.
• this is known as the "Coriolis effect".

• English admiral
• devised a system for comparing wind strenth in 1806.
• scale had 13 wind strengths; calm - Force 0; hurricane - Force 12.

• Canadian geophysicist
• In 1963, came up with idea that became known as the "hotspot" theory
• discovered transform faults

• Canadian geologist
• member of the Geological Survey of Canada (GSC)
  
• in 1884, Tyrell was first explorer to discover the bones of some very large animals in Alberta
  
• began the study of paleontology in Canada
  

• founder of the Geological Survey of Canada (GSC)
• first director of GSC, responsible for mapping Canada's geology
• Canada's tallest mountain is/was? named for him - Mt. Logan, St. Elias Mountains.

Works Cited

Farndon, John. How the Earth Works. Reader's Digest. Singapore, 1996.

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