Do you float better in fresh or salty water? Explain in complete sentence why this may be.

April 8 Learning Log

Essential QuestionHow is the density of water affected by heat and salinity?

Knowing that salt water is more dense than freshwater, describe the impact that you think this has on the oceans? Think about and then write your thoughts down about what impact temperature has on water in terms of density.

April 9 Learning Log

Essential QuestionHow is the density of water affected by heat and salinity?

Water Density

Essential QuestionHow is the density of water affected by heat and salinity?

What percentage of the Earth’s surface is covered by oceans?

71%

Earth has five oceans……

Antarctic or Southern Ocean

Which one is the largest?

Covers 30% of surface of the Earth

Which one has the longest distance north to south?

Which one is mostly in the southern hemisphere?

Which one is the smallest?And mostly in the Northern Hemisphere

Seas: are smaller than oceans and are partly or mostly landlocked.

Origin of the OceansScientists hypothesize that Earth’s water

could have originated from two sources:–Volcanism–Comets

Ocean water is a mixture of gases and solids dissolved in water

Which two substances are the most abundant in seawater?

Chloride, Cl

Sodium, Na

Constituents of Seawater

What is salinity?• A measure of dissolved solids (salts)in

water

• Expressed as grams of salts/ kilogram of water or parts per thousand(ppt)

• Sometimes measured in PSU (practical salinity units) using electrical conductivity

• Avg. salinity of seawater is 35ppt or 3.5 %

Salt is naturally added to and removed from seawater.• Salt added to sea by

– Volcanic eruptions– Erosion of rocks

which dissolve in water

• Salt is removed from sea by– Sea spray– Marine organisms– Formation of

evaporites (chemical rock)

Factors affecting salinity…..

RERUN Water Salinity Density Lab

RECALL: Summarize what was done in the lab demo.

EXPLAIN: Explain the purpose of the labRESULTS: Describe the results of the labUNCERTAINTIES: Describe what you are

still unsure aboutNEW: Write at least two new things that

you learned from this lab

Temperature• Ocean water has

the ability to absorb sunlight which heats the water

• Factors that affect the temperature:–Latitude–Depth–Shore proximity

OCEAN LAYERING

RERUN Water Temperature Lab

RECALL: Summarize what was done in the lab demo.

EXPLAIN: Explain the purpose of the labRESULTS: Describe the results of the labUNCERTAINTIES: Describe what you are

still unsure aboutNEW: Write at least two new things that

you learned from this lab

DensityTwo factors affect density:

–Salinity Halocline – layering of ocean

water due to different salinity levels)

–Temperature Thermocline – layering of ocean water based on different temperatures

Answer the Essential Question in your learning log