Plate Tectonics and the Ocean Floor © 2011 Pearson Education, Inc.

Which is Which?

Continental Drift In 1912 Alfred Wegener proposed that millions of years ago all of the continents were part of one supercontinent called Pangaea.

Evidence for Continental Drift Wegener proposed Pangaea – one large continent existed 200 million years ago Panthalassa – one large ocean Noted puzzle-like fit of modern continents

Evidence for Continental Drift Matching sequences of rocks and mountain chains Similar rocks on different continents

Evidence for Continental Drift Same fossils found on continents that today are widely separated © 2011 Pearson Education, Inc.

At first the hypothesis of Continental Drift was not accepted. Now, widely accepted, it has become incorporated into the Theory of Plate Tectonics.

Continental Drift https://www.youtube.com/watch?v=_5q8hzF9VVE

Theory of Plate Tectonics Lithosphere – tectonic plates that float on ductile asthenosphere Large scale geologic features occur at plate boundaries An early Theory? https://www.youtube.com/watch?v=Hf74Sp0Xe6Q&feature

Plate Tectonics: A new way of thinking Paradigm Shift: Change in world view Shape of the Earth Continental drift Sustainability (?) The theory of Plate Tectonics caused a Paradigm shift in how the Earth moves and how new crust is created.

Marie Tharp Mapped the Ocean floor. In 1952 she identified a key feature of the ridge dividing the North Atlantic. This was a controversial assertion during the decades-long debate over continental drift. By the time Marie retired in 1983, plate tectonics had been widely accepted; she had witnessed, and help to foster, a complete transformation of her field. complete transformation of her field.

Plate Tectonic Processes

Plate Tectonics https://www.youtube.com/watch?v=ZTRu620bIsE

A Little Lesson on Longitude and Latitude

Latitude & Longitude Latitude is distance north or south of the Equator and longitude is distance east or west of the prime meridian. Both are measured in terms of the 360 degrees (symbolized by °) of a circle. Imaginary lines of latitude and longitude intersect each other, forming a grid that covers the Earth and helps us locate points on it.  

Latitude The Equator is the line of 0° latitude, the starting point for measuring latitude. The latitude of the North Pole is 90° N, and that of the South Pole is 90° S. The latitude of every point in between must be some degree north or south, from 0° to 90°.

Longitude The line which runs through Greenwich in  London is called the Greenwich Meridian or Prime Meridian.  The Prime Meridian is 0° longitude. •The Earth is then divided into 180°east and 180°west. •The International Date Line lies at  180°east/west

Longitude & Latitude Assignment Complete the Longitude & Latitude Assignment. Due to be passed in: Wednesday September 9th