Notes, summaries, assignments, exams, and problems for Geology

Oceanography: Earth's Marine Realm

Ocean Coverage and Resources

Oceans cover 71% of Earth's surface and hold 97% of its water. They provide crucial resources, including one-third of natural gas and oil, 16% of protein, and 50% of our oxygen.

Maps and Projections

A map is a representation, usually on a flat surface, of a region of Earth or the heavens. A projection is the image of a geometric figure reproduced on a line, plane, or surface.

Types of Maps:

• Political
• Physiographic
• Geologic
• Topographic
• Bathymetric

Ocean Provinces

• Continental Margins: Shallow areas close to shore.
• Deep-Ocean Basins: Deep-water areas farther from land.
• Mid-Ocean Ridge: A submarine mountain range.

Geological Features

Hot spots are plumes originating from the core-mantle boundary.... Continue reading "Oceanography: Exploring Earth's Vast Marine Realm" »

Warm Area Biomes

Origin of Terrestrial Atmospheres

Venus, Earth, and Mars received their atmospheres through outgassing. Chemical reactions caused CO₂ on Earth to dissolve in oceans and go into carbonate rocks, like limestone. Mars lost much of its atmosphere through impacts.

Formation of the Maria

• The Moon once had a molten interior.
• Several large impacts made huge crater basins.
• This “runny” lava filled in the basins.

Mercury: A Dead Planet

• No atmosphere.
• Has no maria, but small lava plains.
• Has fewer craters than the Moon.
• Craters are shallower than the Moon's due to higher gravity on Mercury.
• Evidence for tectonic processes.
• Evidence for ice at the North Pole.

Mars: Mountains and Canyons

• Mountains and canyons.
• Volcanoes.
• Thin atmosphere.
• No plate tectonics; volcanoes

Jovian Planets and Their Numerous Moons

Jovian planets are known for their abundance of moons. We can categorize these moons into three groups:

Moon Classifications

1. Small Moons: These moons, less than 300 km across, lack a spherical shape and are likely captured asteroids.
2. Medium Moons: Ranging from 300 to 1,500 km in diameter.
3. Large Moons: These moons exceed 1,500 km in diameter. Both medium and large moons likely formed like planets from the "mini-Solar nebulae" surrounding the Jovian planets.

Jovian moons primarily consist of ice. Due to the lower melting point of ice compared to rock, less heating is needed to create molten cores. This allows for volcanism and tectonics to occur. Tidal heating, another significant heat source, plays a crucial... Continue reading "Exploring the Jovian Moons: A Comprehensive Guide" »

Write the schedule of the main big bang events.

Near Earth Asteroids (NEAs)

Asteroids that cross the orbits of inner planets.

Comets

Icy counterparts to asteroids, formed beyond the frostline.

Kuiper Belt

Objects outside the orbit of Neptune to the beginning of the Oort Cloud.

Asteroids

• Small, naturally formed solid bodies that orbit the Sun.
• Airless and show no detectable outflow of gas or dust.
• 18 different compositional types, ranging from solid metal to soggy dirt clods.
• Most are"rocky" consisting of common minerals and free metal. -"Iron" composed of almost pure metal (mostly iron and nickel). -"Carbonaceous Chondrite" composed of rocky material and carbon-rich compounds.

Asteroid Facts

• Rocky leftovers of planet formation.
• Largest is Ceres, diameter ~1,000 km.
• 150,000 in catalogs, and probably over

Conditions for Life

Several key factors make life on Earth possible:

• Water
• A magnetic field
• A protective atmosphere
• Carbon compounds
• An energy source

Biotic and Abiotic Factors

Biotope: The non-living part of an environment, including all abiotic factors.

Biocenosis: All living things from every species within a defined area that provides the necessities for survival.

Ecosystem: A natural environment where living things interact with each other and their surroundings.

Trophic Levels

Ecosystems often have distinct trophic levels:

• Tertiary consumers
• Secondary consumers
• Primary consumers
• Producers

Predation

Predation is an interspecific relationship where one living thing kills another for food.

Soil Composition

Topsoil: Composed of partially decomposed organic matter... Continue reading "Understanding Our Ecosystem" »

Continental Environments

Fluvial (River) Environments

• Stream/river channels
• Sand bars
• Levees
• Floodplains

Lacustrine (Lake) Environments

• Vary in depth, salinity, biological activity, and sediment
• Source sand and mud

Aeolian (Desert) Environments

• Little to no annual precipitation
• Low vegetation
• High wind
• Transport of sand grains
• Dunes contain well-sorted, well-rounded, and frosted (scratched during wind transport) sand grains sand and dust

Paludal (Swamp) Environments

• Area of anoxic (deoxygenated) water where plant material accumulates but cannot decompose (coal)
• Very low energy environment

Glacial Environments

• Glacial meltwater and sediment transport
• Sand, mud, gravel

Transitional Environments

Deltas

• Fan-shaped deposits of sediment
• Coarser sediment is commonly deposited