EPS SCI 15 Lecture 3 Review

The Scientific Method is used by _____ to build ____________.

Scientists, accurate models of natural phenomena

The Scientific Method usually starts with __________, which leads to the generation of a _________, followed by ____________ to test the prediction. If untestable, the hypothesis is _______.

observations, testable hypothesis, data collection, rejected

A Scientific Theory represents:

a hypothesis that has been confirmed by repeated independent experimental tests.

The Plate Tectonic Theory is a:

fundamental, unifying theory, which explains the shape of theEarth's surface.

Observations that lead to the development of the Plate Tectonic Theory are:

1. Continental jigsaw puzzle

2. Geologic features that line up across continents

3. distribution of earthquakes

4. Magnetic orientation of seafloor rocks

5. thickness/age of ocean sediments

The lithosphere consists of ___________ (~50 total) that are thin (~100 km thick), internally _____ and constantly _______ (2-15 cm/yr).

14 major plates, rigid, in motion

New oceanic lithosphere is ________ at mid-ocean ridges; ancient oceanic lithosphere is

___________ at deep-sea trenches (subduction zones).

generated, consumed

The key to lithosphere recycling is:

convection (heat transfer by moving "fluid").

There are three types of plate boundaries:

(1) divergent, (2) convergent, (3) transform

Divergent boundaries:

form new seafloor at spreading zones (e.g., Mid-Atlantic Ridge)

At convergent boundaries, one plate subducts under another plate. There are three types of subduction zones:

(1) ocean-continent (e.g., Peru-Chile trench), (2) ocean-ocean (e.g., Aleutian trench), (3) continent-continent (e.g., Himalaya).

At transform boundaries:

two plates slide past each other horizontally (e.g., San Andreas Fault).

All today's continents were once united into one giant continent, called ________, which ________ to form the continents we see today. But what we see today is only a snapshot. The plates are still moving. Earthquakes are a reminder of this activity

Pangaea, drifted apart