The document summarizes several key points about the properties of water and oceans: 1) Moderate temperatures on Earth are maintained by oceans, which moderate temperature changes between day and night and seasons, preventing equatorial oceans from boiling and polar oceans from freezing solid. 2) Salinity in open oceans ranges from 33-38 parts per thousand but varies more in coastal areas due to freshwater influx or evaporation. 3) Most of Earth's water (97.2%) is contained in oceans, with the remaining portions found in glaciers, groundwater, lakes, soil, and the atmosphere.

1.  Moderate temperature on Earth’s surface
 Equatorial oceans do not boil
 Polar oceans do not freeze solid
 Marine effect
 Oceans moderate temperature changes from day to
night and during different seasons
 Continental effect
 Land areas have greater range of temperatures from
day to night and during different seasons
© 2011 Pearson Education, Inc.

2. © 2011 Pearson Education, Inc.

3.  Density of water increases as
temperature decreases.
 Thermal contraction
 From 4 C to 0 C the density of
water decreases as temperature
decreases.
 Ice is less dense than water.
 Changes in molecular packing
 Water expands as it freezes.
 Dissolved solids (salts) also reduce
the freezing point of water. EX:
putting salt on icy sidewalks.
 Most seawater never freezes.
© 2011 Pearson Education, Inc.

4. © 2011 Pearson Education, Inc.

5.  Total amount of
dissolved solids in
water including
dissolved gases
 Excludes dissolved
organics
 Ratio of mass of
dissolved substances to
mass of water sample
© 2011 Pearson Education, Inc.

6.  Expressed in parts per thousand (ppt)
 Typical ocean salinity is 35 ppt (o/oo)
© 2011 Pearson Education, Inc.

7. © 2011 Pearson Education, Inc.

8.  Evaporation
 Chemical analysis–titration
 Measure amount of halogens (Cl, Br, I, F) (chlorinity)
© 2011 Pearson Education, Inc.

9.  Evaporation
 Chemical analysis–titration
 Measure amount of halogens (Cl, Br, I, F)
(chlorinity)
 Electrical conductivity
 Salinometer
© 2011 Pearson Education, Inc.

10. © 2011 Pearson Education, Inc.

11.  Open-ocean salinity is
33–38 o/oo
 In coastal areas salinity
varies more widely.
 An influx of freshwater
lowers salinity or creates
brackish conditions.
 A greater rate of
evaporation raises
salinity or creates
hypersaline conditions.
 Salinity may vary with
seasons (dry/rain).
Great Salt Lake, UT
© 2011 Pearson Education, Inc.

12.  Decreasing salinity
– adding fresh
water to ocean
 Runoff, melting
icebergs, melting
sea ice
 Precipitation
© 2011 Pearson Education, Inc.

13.  Increasing salinity
– removing water
from ocean
 Sea ice formation
 Evaporation
© 2011 Pearson Education, Inc.

14. © 2011 Pearson Education, Inc.

15.  97.2% in the world ocean
 2.15% frozen in glaciers and ice caps
 0.62% in groundwater and soil moisture
 0.02% in streams and lakes
 0.001% as water vapor in the atmosphere
© 2011 Pearson Education, Inc.

16. © 2011 Pearson Education, Inc.

17. © 2011 Pearson Education, Inc.

18.  Acid releases a hydrogen ion (H+) when
dissolved in water.
 Alkaline (or base) releases a hydroxide ion
(OH-) in water.
© 2011 Pearson Education, Inc.

19.  Measures hydrogen ion concentration
 Low pH value, acid
 High pH value, alkaline (basic)
 pH 7 = neutral
 Pure water
© 2011 Pearson Education, Inc.

20.  High latitudes
 Low salinity
 Abundant sea ice melting, precipitation, and
runoff
 Low latitudes near equator
 Low salinity
 High precipitation and runoff
 Mid latitudes
 High salinity
 Warm, dry, descending air increases evaporation
© 2011 Pearson Education, Inc.

21. © 2011 Pearson Education, Inc.

22. © 2011 Pearson Education, Inc.