Marine Bio chapters 2 & 3

How much of the earth’s surface is covered by the world’s ocean?

71%

The largest percentage of the world’s ocean is found in the…

Southern Hemisphere

What are the major ocean basins?

Atlantic, Arctic, Indian, and Pacific oceans

What is the worlds smallest and shallowest ocean?

the Arctic ocean

What is the worlds largest and deepest ocean?

Pacific Ocean

What does the name “Southern Ocean” refer to?

The waters surrounding Antarctica

What was the Big Bang?

The giant cosmic explosion that occurred 13.7 billion years ago and created the universe

What is density?

the mass of a substance per unit volume

There is evidence that the Earth and the rest of the solar system formed about …

4.5 million years ago

The semisolid layer of the Earth found below the crust and outside of the core is called the…

Mantle

The earth’s magnetic field is thought to be caused by movements of liquid metal in which of the Earth’s layers?

Outer core

The thinnest layer of the Earth is the…

Crust

What is different about oceanic crust from continental crust?

Oceanic crust is thinner, denser, geologically younger, lies below sea level, and consists of a dark mineral called basalt

Describe mid-ocean ridges

its a continuous chain of submarine volcanic mountains that encircles the globe formed by plate tectonics where new oceanic crust is created. it is the largest geological feature on earth

Describe lithospheric plates

earth surface is covered by a rigid layer composed of crust and upper-mantle which is called the lithosphere. The lithosphere is broken into a number of plates called the lithospheric plates or tectonic plates. The lithosphere is made up of either or both continental and oceanic crust. It floats on a denser more plastic layer of the upper mantle called the asthenosphere. it is destroyed at trenches

Trenches are …

a system of deep depressions in the sea floor, formed when tectonic plates collide and the denser plate bends and slides beneath the lighter plate into the Earths mantle.

Subduction

the downward movement of the plate into the mantle. this creates earthquakes and volcanoes

Fault

The friction zone along shear boundaries

Island arc

volcanic island chains that associated with the trenches follow the trenches curvature EXAMPLE Aleutian and Mariana islands

Types of lithospheric plate boundries

divergent, convergent, and transform boundaries

Shear boundary

the transitional zone where frictional forces and velocity changes occur between a moving substance and a stationary surface, or between two adjacent streams moving at different speeds

Evidence of plate tectonics is provided by …

seafloor spreading

The vast single world ocean that was present about 200 million years ago

Panthalassa

Lithogenous sediments come from …

weathering and erosion, and are transported to the ocean by rivers, wind, and gravity

study the continental margin

ba ba black sheep

active continent margins

located at plate boundaries, frequent earth quakes, common volcanoes, and rugged steep shorelines

Passive margins

located within a plate and away from boundaries, rarely earthquakes, no volcanoes, and low flat wide continental shelf shorelines

Black smoker stacks are…

hydrothermal vents on the ocean floor where super heated water erupts from the seafloor. it forms as a result of metallic sulfides minerals reacting with Seawater

The most biologically rich part of the ocean is the…

continental shelf

abyssal plane

the deep sea floor

who proposed the first detailed hypothesis of continental drift

Alfred Wegener

Hydrogen bonds in water molecules are formed between …

a hydrogen atom of one water molecule and the oxygen atom of an adjacent molecule

When water cools, but does not freeze, the molecules …

move slower and pack closer together, taking up less space.

What is the state of water at a temperature of 4 degrees C?

Maximum density point, fresh water gets denser as it gets colder but only until 4 degrees C, below that it gets less dense.

Hydrogen bonds …

make ice less dense than water

Which ions comprise about 85% of the solutes in seawater ?

Sodium and chloride

Salinity of water is generally expressed in…

Parts per thousand

The rule of constant proportions states…

the relative amounts of the various ions in seawater are always the same

Salinity of seawater increases…

as water evaporates (increased evaporation) or as ice freezes

The heat capacity of water is…

much higher compared to other naturally occuring substances

What property is unique to water due to its molecular structure?

It is less dense as a solid than a liquid, allowing ice to float

The Secchi disk is used to indirectly estimate..

the type of light that is absorbed by water

Water being less dense as a solid than a liquid is important for organisms because…

It keeps ice floating on top, insulating the water below. If ice was more dense, water bodies would freeze from the bottom up, killing aquatic organisms.

Pressure increases with depth by adding one atmosphere of pressure for every…

10 meters of depth

The Coriolis effect is the direct result of …

Rotation of the Earth

The factor that most affects wind patterns in the atmosphere of the Earth is …

the heat energy from the sun

Trade winds …

do not move straight toward the equator but are bent by the Coriolis effect, causing them to develop between 30 degrees north and 30 degrees south

Gyres are…

Large circular systems of surface currents

The major surface currents of the oceans rotate counter clockwise…

In the Southern Hemisphere

In what location does a cold current flow almost into the equator?

the Pacific coast of South America

What is the Ekman spiral?

a process where wind pushes surface water, Coriolis deflects it 45 degrees to the right (northern hemisphere) Each deeper layer moves slower and more deflected, forming a spiral, it occurs as a result of wind and the Coriolis effect

What is the highest and lowest part of a wave?

The crest is the highest part of a wave and the trough is the lowest part

Waves size is affected by the…

fetch, the amount of open water that winds blow over

Spring tides occur when…

the Sun, Moon, and Earth align during full and new moons, and the gravitational pulls of the Sun and Moon combine producing the greatest tidal range (highest tides and lowest tides)

A full tidal cycle lasts…

24 hours, 50 minutes

Neap tides

sun and moon at right angles (first and third quarter moon) creating the smallest tidal range (moderate tides

diurnal tides

one high and one low tide per day

Semidurnal tides

two high and two low tides per day, roughly equal heights

mixed tides

two high and two low tides per day but unequal heights

Thermocline

the zone in the ocean where temp drops rapidly with depth, separating warm surface water from cold deep water, sitting between warm and cold layers

How does the oxygen content of the ocean compare to the air that humans breathe?

Lower oxygen content

Tropical organisms like corals are adapted to…

warm, stable, nutrient-poor waters. they thrive in clear, sunlit, shallow water where temps are warm year-round

Forces that cause water movements lead to the mixing of the entire ocean once every…

1,000 years