Chapter 1 The Earth System

Question 1

What is the Scientific Method?

Answer 1

General procedure for discovering how the universe works through systematic observations and experiments.

Question 2

What is a scientific theory?

Answer 2

A coherent set of hypotheses that explains some aspect of nature

Question 3

State Earths major layers and thickness and their masses expressed as a percentage of Earths total mass.

Answer 3

Crust 0-40km 0.4% earths mass

Mantle 40-2890km 67.1% Earths mass

Liquid iron outer core 2890-5150km 30.8% Earths mass

Solid iron inner core 5150-6370km 1.7% Earths mass

Question 4

What is the Mohorovicic discontinuity?

Answer 4

Boundary which separates the crust composed of low-density silicates, which are rich in aluminum and potassium, from the higher density silicates of the mantle,which contain more magnesium and iron.

Question 5

State the chemical composition of earths major layers.

Answer 5

Inner core, 94% Iron, 6% Nickel

Outer core, 85% Iron, 5% Nickel, 5% Oxygen, 5% Sulfur

Mantle, 44% Oxygen, 23% Magnesium, 21% Silicon, 6% Iron, 2% Calcium, 2% Aluminum

Crust, 46% Oxygen, 28% Silicon, 8% Aluminum, 6% Iron, 4% Magnesium, 2% Calcium

Question 6

What is the Earth System?

Answer 6

All the parts of planet earth and their interactions such as the Climate system, the Plate Tectonic system, the Geodynamo system.

Question 7

The Climate system energized by earths solar radiation involves interactions between?

Answer 7

The Atmosphere, Cryosphere, Hydrosphere, Biosphere

Question 8

What is the Atmosphere?

Answer 8

Gaseous envelope extending from the Earth’s surface to an altitude of about 100km

Question 9

What is the Cryosphere?

Answer 9

Polar ice caps, glaciers, and other surface ice and snow

Question 10

What is the Hydrosphere?

Answer 10

Surface waters comprising all oceans, lakes, rivers and ground waters

Question 11

What is the Biosphere?

Answer 11

All organic matter related to life near Earth’s surface

Question 12

The Plate Tectonic System involves interactions between?

Answer 12

The Lithosphere, Asthenosphere, Deep Mantle

Question 13

What is the lithosphere?

Answer 13

Strong, rocky outer shell of the solid Earth that comprises the crust and uppermost mantle to an average depth of about 100km :forms the tectonic plates

Question 14

What is the asthenosphere?

Answer 14

Weak, ductile layer of mantle beneath the lithosphere that deforms to accommodate the horizontal and vertical motions of plate tectonics

Question 15

What is the Deep Mantle?

Answer 15

Mantle beneath the asthenosphere, extending from about 400km deep to the core-mantle boundary(about 2900 km deep)

Question 16

The Geodynamo involves interactions between?

Answer 16

Inner core and Outer core

Question 17

How old is the Earth?

Answer 17

4.56 billion years

Question 18

Major events observed in the geologic record during the Hadean?

Answer 18

4560 Ma Earth and planets form

4510 Ma Moon forms

4470 Ma Oldest lunar rocks

4000 Ma Oldest continental rocks

Question 19

Major events observed in the geologic record during the Archean?

Answer 19

3800 Ma Evidence of erosion by water

3500 Ma Record of Magnetic field fossils of primitive bacteria

2700 Ma Start of rise of atmospheric oxygen

2500 Ma Major phase of continent formation completed

Question 20

Major events observed during the Phanerozoic?

Answer 20

542 Ma evolutionary “Big Bang”

420 Ma Earliest land animals

125 Ma Earliest flowering plants

5 Ma First hominids

0.2 Ma First appearance of Homo Sapiens

Question 21

What is geology?

Answer 21

Geology is the study of the earth, it’s history, it’s composition and internal structure and it’s surface features.