1. The Hydrologic System and the Tectonic System
2. Geologic Systems
The Hydrologic System and the Tectonic System

2. What is a Natural System?
Group of natural, interdependent parts or components
Interactions between parts forms the system
Forces drive the system
All systems tend toward a state of lowest energy (or maximum disorder--entropy) called equilibrium
Earth’s two major systems are:
Hydrologic System
Tectonic System

3. Equilibrium in Geologic Systems
Analogous to gravitational potential energy
All geologic systems strive to minimum energy state
Winter (2001)

4. Hydrologic System System of moving water Hydrologic System Rivers
Oceans, Lakes
Glaciers
Groundwater
Water Vapor in Atmosphere
Hydrologic System
Erosion
Transportation of Sediment
Deposition of Sediment
Creation of Numerous Landforms

5. Hydrologic System

6. What Forces Drive this System?
Solar Radiation
Average ~342 W/m2 = ~342 joules/sec m2
Causes evaporation
Gravity
Pulls water down slopes
Causing erosion, transportation of sediment
Atmospheric convection

7. Global Patterns in the Hydrologic System
How does atmospheric circulation affect the movement of water in the hydrosphere?
Where will air rise?
Where will air sink?
What holds more water vapor?
Cool air or hot air

8. Uneven Solar Heating
Dr. Kowallis -- Geology 330

9. Dr. Kowallis -- Geology 330

10. Magnitude of Hydrologic System
Imagine what would happen if water delivered to the continents stopped going back to the sea
Sea level would drop …..

11. Magnitude of Hydrologic System
Imagine what would happen if water delivered to the continents stopped going back to the sea
Sea level would drop 1 m/y
Has this ever happened?

12. Magnitude of Hydrologic System
Imagine what would happen if water delivered to the continents stopped going back to the sea
Sea level would drop ~1 m/y
Has this ever happened?
During last ice age
Siberia and Alaska connected
England and France connected
New York City 100 km inland

13. Where is Water Found in the Hydrologic System?
Oceans 97%
Of that not in Ocean
Ice %
Lakes %
Rivers %
Atmosphere %
97%
Dr. Kowallis -- Geology 330

14. Subsystems of the Hydrologic System
River Systems
Glacial Systems
Groundwater Systems
Shoreline Systems
Eolian Systems
Each creates
Landforms
Bodies of rocks
Operation of Energy on Matter
Dr. Kowallis -- Geology 330

20. Dr. Kowallis -- Geology 330

27. Hydrologic System: Summary
A natural system is a group of interdependent components that interact to form a unified whole and are under the influence of related forces. The materials in a system change in an effort to reach and maintain equilibrium.
Earth's system of moving water--the hydrologic system--involves movement of water in rivers, as groundwater, in glaciers, in oceans, and in the atmosphere.
Heat from the Sun is the source of energy for Earth's hydrologic system. Gravity drives it downhill. The distribution of solar energy creates a vast global pattern of convective transport of water vapor.
As water moves, it erodes, transports, and deposits its sediment, creating distinctive landforms and rock bodies.
Earth has a dynamic hydrologic system because of its composition (i.e., water-rich), its size (able to hold out gassed vapor), and its distance from the Sun (warm enough for liquid water to exist over much of its surface yet cold enough for ice at the poles and high latitudes).

28. Earth’s Tectonic System

29. Tectonic System
A system of moving plates of lithosphere sliding over the weak asthenosphere
Movement driven by convection and Earth’s internal hear
Radioactive decay of K, U, and Th
Heat released as Earth tries to reach equilibrium with cold space

30. Tectonic System

31. Plate Boundaries

32. Divergent plate boundary
Midocean ridge

33. Divergent Plate Margins
Rifted continent
Mid-oceanic ridge with subsiding rift margins

35. Divergent Plate Boundaries
Continental rifts
Midocean ridges
New ocean basins
Volcanoes
Shallow earthquakes

36. Tectonic System: Convergent plate margins

37. Convergent plate margin: Ocean-Continent
Andes Mountains

38. Convergent Plate Margins
Oceanic-Continental
Subduction Zone
Volcanoes in a continental arc
Cascade Range, NW USA

40. Mexican Volcano: 2003

44. Convergent Plate Boundaries
Folded mountain belts on continents
Deep sea trenches
Volcanic chains on continents
Volcanic island arc in oceans
Abundant earthquakes—shallow to deep

45. Tectonic System: Transform Plate Margin

46. Transform plate boundaries
Long, straight faults
Movement is horizontal
Shallow earthquakes are abundant

47. Dr. Kowallis -- Geology 330

48. Mantle plumes

49. Dr. Kowallis -- Geology 330

50. Mantle Plumes: Hot spots
Not plate boundaries
Rising plumes of hot mantle material
Within plate volcanoes
Broad flexures of lithosphere

52. Earth’s Tectonic System