eexam 1 Flashcards
What is the scientific method?
Hypothesis testing.
What are the key components of the hydrologic cycle?
Evaporation, rain, runoff.
What percentage of Earth’s surface is covered by oceans?
About 71%.
Where is most of Earth’s freshwater located?
In glaciers.
When did the Big Bang occur?
13.8 billion years ago.
When did Earth form?
4.54 billion years ago.
What is the origin of Earth’s atmosphere and ocean?
Volcanic outgassing, impacts, cooling, condensation of water.
What was the composition of the early atmosphere?
Water vapor, CO₂, N₂, SO₂.
Who were major contributors to early oceanography?
Phoenicians, Greeks, Egyptians, Chinese, Polynesians.
What was the significance of the Library at Alexandria?
3rd-century BCE archive; Eratosthenes calculated Earth’s circumference.
Who developed the longitude-latitude system?
Hipparchus and Ptolemy.
Who invented the marine chronometer for accurate longitude?
John Harrison.
What was James Cook’s contribution to oceanography?
Mapped the Pacific with HMS Endeavour.
What was the HMS Challenger’s significance?
First global oceanographic expedition.
What are modern ocean exploration vessels?
Joides Resolution, Chikyu.
How do we know about Earth’s internal structure?
Seismology (P & S waves).
What are Earth’s chemical layers?
Crust (basaltic, granitic), Mantle (iron, magnesium-rich), Core (Fe, Ni).
What are Earth’s physical layers?
Lithosphere, Asthenosphere (partly molten), Outer core (liquid), Inner core (solid).
What defines a mineral?
Naturally occurring, crystalline solid, specific chemical composition.
How do we differentiate minerals?
Properties like density, cleavage, color, hardness.
How does radioactivity contribute to Earth’s heat?
Decay of isotopes generates heat; used in radiometric dating.
What is isostasy?
Buoyant balance of crust floating on the mantle.
Who proposed continental drift?
Alfred Wegener.
What evidence supported continental drift?
Fossils, rock formations, continental fit.
Who discovered sea-floor spreading?
Hess and Dietz.
What confirms sea-floor spreading?
Magnetic anomalies, ocean crust dating.
What are the three types of plate boundaries?
Divergent, Convergent, Transform.
What landforms are associated with each boundary?
Divergent: mid-ocean ridges.
Convergent: trenches, volcanic arcs, mountains.
Transform: faults, earthquakes.
What drives plate movement?
Mantle convection, ridge push, slab pull.
What are hot spots?
Isolated volcanic regions (e.g., Hawaii).
What tools are used to study ocean depth?
Echo sounding, sonar, multibeam, satellite altimetry.
What is the average ocean depth?
~3,700 m.
What are the two types of continental margins?
Passive (no subduction) and Active (subduction, volcanism).
What are the three parts of the continental margin?
Shelf, Slope, Rise.
How do glaciations affect sea levels?
Cause sea levels to rise and fall (>100 m shifts).
What is a turbidity current?
Fast-moving sediment-laden flow down slopes.
What is the composition of the deep ocean floor?
Basaltic crust, sediments.
What are hydrothermal vents?
Hot springs at mid-ocean ridges, home to unique life forms.
What is the abyssal plain?
Flat, deep ocean floor covered in sediment.
What are seamounts and guyots?
Volcanic islands that sink and flatten.
What is the deepest ocean trench?
Mariana Trench (Challenger Deep).
What are the main types of ocean sediment?
Terrigenous, Biogenic, Hydrogenous, Cosmogenous.
What is the Carbonate Compensation Depth (CCD)?
Depth below which calcium carbonate dissolves (>4,000 m in mid-ocean).
What modern program studies ocean sediments?
IODP (International Ocean Discovery Program).
