ESSC Test 2
Terms
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- Who is Alfred Wenger?
- A German meteorologist who was an Arctic explorer. He found tropical fossils on Greenland.
- Pangaea
- How the Earth was before continental drift
- Gondwanaland
- The southern part of Pangaea where similar plant fossils were found
- Laurasia
- Northern part of Pangaea
- Evidence for Continental Drift
-
-Match of continental outlines
-Continuity of mountain belts and other geological formations across continental boundaries
-Similar fossils on separate continents
-Glacial deposits and otoher paleoclimate indicators - Continental Shape
- Shoreline similarity using the continental shelf
- Continuity of mountain belts
- Similar geology and ages of the Appalacian and Caedonides; Cape Fold and folded rocks in Buenos Aires;
- Fossil similarity
-
Upper paleozoic fern Glossopteris in Africa, S. America, India, Austrailia, and Antarctica
-Large seeds
Mesosaurus-fresh water dino and land-dwelling dinos - Glacial Deposits and Paleoclimate
- Glacial deposits found in arid climates and similar aged and types occur in all southern continents
- Why was Wegeners idea rejected?
-
-Continent fit wasn't perfect
-Rock unit correlation was weak
-Tillites were't glacial deposits
-Northern hemisphere coals weren't tropical
-Errors in the calculated motion of Greenland
-He wasn't a geologist
-No Mechanism for moving continents - Crust
-
Thin
oceanic and continental - Lithosphere
- crust and cool uppermost part of the mantle
- Mantle
-
thick
includes asthenosphere which is asphalt-like - Inner Core
- Solid-Iron, Nickel alloy
- Outer Core
- Magnetic-Iron and Nickel alloy
- Evidence for Plate Tectonics
-
Paleomanetism
Magnetic Reversals
Earthquake and Volcano Distribution
Lithospheric Plates
Plate Boundaries - Paleomagnetism
- Magnetite in the basalts of Greenland were not pointing to the present day poles
- Magnetic Reversal
-
-New ocean floor basalts become magnetized according to the existing magnetic field
-Parallel to the mid-ocean ridge
-Both sides equal in size and polarity
-Started seafloor spreading - Earthquake and Volcano Patterns
- earthquakes occur near trenches, as well as volcanoes
- Lithospheric Plates
-
They are in motion and constantly changing
7 major plates-Pacific - Different Types of Plate Boundaries
-
Divergent-moving apart
Convergent-coming together, o-o, o-c, c-c
Transform-sliping past one another - Oceanic Oceanic
- Midocean ridge or trench
- Oceanic Continetal
- Trench Volcano
- Whats formed at Divergent boundaries?
- Volcanoes Rift Valley
- Transform
- Transform Fault-San Andreas
- Convection
- Molecules vibrate faster because they are being heated. They rise up because they become less dense. They then get cooler, move slower, and sink.
- Volcano
- A weak spot in the Earth's crust where magma comes to the surface
- Magma
- molten rock forming substances, gases, and water vapor
- Where are volcanoes found?
-
Plate boundaries
Ring of Fire in the Pacific ocean - Parts of a volcano
-
crater
Lava
Magma
Pipe
Vent - How does magma rise?
- It comes from the asthenosphere under great pressure. It's less dense than the surrounding material, so it rises and gets trapped under rock or reaches the surface. Gases in magma rush out, carrying the magma with it.
- What does eruption depend on?
-
gas in magma
viscosity of magma
temperature of magma
silica content of magma - 3 stages of volcano
-
Active
Dormant
Extinct - Types of volcanoes?
-
shield
cinder cone
composite - Shield Volcano
-
wide, gently sloping mountain
Olympus Mons, Mars - Cinder Cone Volcano
-
ash, cinders, and bombs pile around a vent in a sttep hill
Little Lake, CA - Composite Volcanoes
-
tall cone shaped where lava alternates ash, cinders, and bombs.
Mt. Fuji, Japan - Earthquake
- A vibration of Earth produced by the rapid release of energy from the focus
- What are earthquakes associated with?
- Faults; stress
- Body Waves
- Primary and Secondary
- Primary Waves
-
Push-pull
Longitudinal - Secondary Waves
-
Moves through solids
Transverse waves-travel like an "S" - Surface Wave
-
Like ocean swells-up and down or side to side motion
LOTS OF DAMAGE - Quantity of Energy released from an Earthquake
- Magnitude
- How can you measure the size of an EQuake?
-
Richter Scale
Moment Magnitude - what is a tsunami?
- displacement in ocean floor causing a "wave" which increases in size before reaching the shore