Oceanography week 1

23) What is the largest migration of life on the planet, explain?

1000 million sea creatures ascend from the deep ocean to search for food. They graze on the phytoplankton for food. Other marine creatures follow them in search of food.

15) About what percent of Earth's water is found in the ocean.

97.2%

25) Why do grey whales migrate such great distances?

Grey whales migrate to feast and grow in the waters of the Arctic in order to mate and give birth.

16) On a planetary scale, the ocean comprises about what percent of Earth's mass?

On a planetary scale, the ocean accounts for slightly more than 0.02% of the earth's mass and 0.13% of its volume.

18) What is the largest animal to ever inhabit planet Earth and what does it eat?

The blue whale and it eats krill.

9) Why have satellites been so important regarding understanding the oceans?

-gather large scale dale over a short period of time. -They also provide intricate details such as sea surface temperature, ocean color and transmitters that are used to measure tidal heights and migration of whales.

4) List four reasons to care about the oceans?

1) climate regulation since transports heat from the equator to the poles 2) recreational activities such as kayaking, boating etc. 3) It is a mode of transportation since It covers such a large surface of the earth 4) It is a source of food

17) Compare and contrast the following (hypothesis theory, law, fact)

1)fact is an observation about the world 2)hypothesis a speculation about the natural world that can be tested, verified or disproved by additional observation of experiments. 3)A theory is an elevated version of a hypothesis as a hypothesis ie if it is consistently supported by observation or experiment, the hypothesis is advanced into a "theory", which is essentially a statement that explains observations. 4)A law is like theory however it differs in the sense that summarizes observations as mathematical or verbal expression; a theory provides an explanation for the observation.

12) What percent of Planet Earth is covered with water?

71%

14) What is meant by the statement that stars manufacture heavier elements?

It means that every chemical element heavier than hydrogen, ie most of the atoms that make up the planets, the ocean and living creatures were manufactured by the stars.

22) What is the basis of all life in the ocean?

Phytoplankton

13) Why do scientist think that life started in the oceans?

Scientists think this because they believe that life on earth started from an aggregation of a few basic compounds that were transported to earth by meteors and ultimately crashed into the planet in which they believe that the ocean began to hold these compounds. They conducted lab experiments to prove this and found that the role of water was crucial and virtually all life needed water to survive. This suggested ultimately that living molecules arose somewhere from early in the ocean because all living things need water to survive and suggest that all life on earth is of common origin and ancestry.

7) How can the height above the horizon of the North Star be used in navigation?

The North star does not rise or set during the night and the axis of the earth is pointed at it. The height of the north star in relative to the horizon gives latitude and helps navigation as it provides position at sea through the knowledge of the relative position of the stars.

1) Compare the five main oceans on the planet which is largest/smallest deepest/shallowest ice-covered and unconstrained by landmasses

The Pacific is the largest and deepest ocean. The Atlantic is the second largest and is almost as deep, the Indian ocean is the third largest and is also almost as deep which the arctic is the smallest, shallowest and most ice covered ocean. The Antarctic/ southern ocean connects the pacific, atlantic and indian south of about 50os of latitude and is larger than the atlantic. the pacific is the most unconstrained by land mass followed by the atlantic, indian and the arctic.

19) Why is there so much "life" around volcanic islands (seamounts)?

The deep ocean currents collide with island flanks and deflect upwards, bringing nutrients from the depth upwards.

8) Why was the invention of the "echo sounder" so important for understanding the oceans?

The echo sounder was important as it allowed for the measurement of seafloor bathymetry and essentially the depth of the water. They allow for mapping of the sea floor, in order to look for specimens of interest ie shipwrecks.

21) Why do Hammerhead Sharks come to seamounts?

They come to seamounts for a type of "service" from the other fish ie such as being cleaned off parasites and fungal infections.

5) What two ways did the Phoenicians use to navigate around the Mediterranean Sea?

They used the North star for navigation and explored marine routes through the position of stars, seas, landmarks and the direction of the wind.

24) Why do Sea turtles lay all their eggs on the same day?

To ensure that their hatchings will emerge in such an enormous number that predators on the beach will be frightened and most of them will survive. The weak tides and calm sea allow for less chance of their eggs being washed out by the sand and being taken by the predators.

20) What do Tuna eat and what eats them

Tuna eats small fish and are eaten by sharks.

3) What is special about the Sargasso Sea?

is defined by surrounding ocean currents unlike other sea that are defined either completely or in part by land boundaries.

11) Compare ocean depths to land heights.

ocean is 3682 meters, land elevation is only 840 meters.

10) How is Oceanography different from most of the other sciences?

oceanography is a type of science but it differs in the sense that it is interdisciplinary and integrates the fields of biology chemistry, engineering etc as they apply to the ocean and its surroundings. Marine scientists also specialize in one area of research but have to be familiar with their related specialties and understand the linkages between them.

2) What is the difference between an ocean and a sea?

seas are shallower, smaller and are usually connected to big oceans. Seas are also surrounded by land whereas have larger portions that are unconstrained by landmasses.

6) What is mean by "reverse tribute" and who used this approach during exploration.

was used by the Chinese during which foreigners were granted permission to trade in China in exchange for a "tribute" and exchange of submission.