Grade 8 Science
description
Transcript of Grade 8 Science
![Page 1: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/1.jpg)
Grade 8 ScienceUnit 1:
Water Systems on Earth
Chapter 1
![Page 2: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/2.jpg)
Effects of Water?
Churchill River
![Page 3: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/3.jpg)
Large Ocean Wave
![Page 4: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/4.jpg)
How do you use water?
House Hold Use
Personal UseRecreational Activities
![Page 5: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/5.jpg)
Water Distribution
![Page 6: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/6.jpg)
Only 3% of the Earth’s water is fresh water (no salt).
2/3 of this water is frozen in ice sheets.
Therefore only 1% of the fresh water on Earth is available.
![Page 7: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/7.jpg)
Review of Terms...Definition of Lithosphere: the solid rocky ground of the Earth’s crust.Do not write in pamphlet
![Page 8: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/8.jpg)
Atmosphere: the environment surrounding the Earth.
Do not write in pamphlet
![Page 9: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/9.jpg)
Hydrosphere: All water on Earth. Including that in the lithosphere and atmosphere.
![Page 10: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/10.jpg)
Scientists who study water...
Hydrologist
A person who studies Earth’s water systems and helps to find solutions to problems of water quality and quantity.
Not in pamphlet
![Page 11: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/11.jpg)
Oceanographer: A person who studies all aspects of the ocean. They are concerned with the biology, geology, physics, and mathematics of the ocean.
![Page 12: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/12.jpg)
Why do We Not Run Out of Water??
Because of the: WATER CYCLE
![Page 13: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/13.jpg)
The Water Cycle...
![Page 14: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/14.jpg)
The constant cycling of water through the processes of :
Evaporation&Condensation.condensatio
Water is constantly changing from
(gas liquid) and back again. This driven by the sun’s energy.
![Page 15: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/15.jpg)
Ocean Water vs. Fresh WaterThree ways in which fresh water differs from ocean water are:
1. Salinity 2. Density 3. Freezing point
![Page 16: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/16.jpg)
1. Salinity - Definition-The amount of salt dissolved in a specific amount of water.
salt comes from dissolved solids in the ground and volcanoes.
salt comes from dissolved solids in the ground and volcanoes.
![Page 17: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/17.jpg)
Fresh Water has tiny amounts of salt.
Salt Water Average amount of salt in salt
water is 35 ppt. Salt content varies depending
on location. Increase salt at the equator
and poles
![Page 18: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/18.jpg)
2. Density - Definition -The amount of mass of a substance in a certain unit volume.
*How tightly packed together the material is in a substance.
![Page 19: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/19.jpg)
*Ocean water is more dense than fresh water due to the salt content.
The Dead Sea
![Page 20: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/20.jpg)
3. Freezing Point -Definition -The temperature at which a liquid freezes.
*Fresh water... 0oC*Salt water... -1.9oC
![Page 21: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/21.jpg)
Core Lab ActivitiesActivity 1-3A“Salinity’s Effect on Water
Density”
Graphing Assignment pp60-61
“Temperature & Water Density”
![Page 22: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/22.jpg)
Sources of Fresh Water1. Lakes, ponds and
wetlands2. Streams and rivers3. Ground water4. Run Off5. Glaciers6. Drainage Basins
![Page 23: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/23.jpg)
3. Ground Water...Precipitation that falls on land and sinks out of sight.
Sinks through pores in rocks and goes down to bedrock where it pools.
These pools to us make up “wells”.
![Page 24: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/24.jpg)
Ground Water : Drilling Wells
![Page 25: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/25.jpg)
4. Run Off doesn’t sink into the ground or evaporate.: flows on land.
is affected by: a) ground material, b) amount of rain, c) amount of time it rains, d)slope (steepness) of the land, e)vegetation, f) the amount of development.
![Page 26: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/26.jpg)
5.Glaciers...A moving mass of snow and ice.
Found in areas where it is so cold the snow remains all year.
![Page 27: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/27.jpg)
Glaciers in mountains and on the continent of Antarctica
![Page 28: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/28.jpg)
Glaciers slow down the Water Cycle by storing big amounts of frozen fresh water. Some water thaws in the hot summer months.
They give us information about the Earth’s past climates. ( samples)
![Page 29: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/29.jpg)
Water trapped in glacial ice
![Page 30: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/30.jpg)
6. Drainage Basins
![Page 31: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/31.jpg)
The Ice AgeThe most recent began 120 000 years ago ending
11 000 years ago.Glaciers covered ~ 20% of land on Earth.
![Page 32: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/32.jpg)
![Page 33: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/33.jpg)
Glaciers and Global WarmingIn the last 100 years the average surface temp. Has increased by 0.5oC.
The world’s glaciers are melting at a quicker paces than ever before.
![Page 34: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/34.jpg)
Melting Greenland Glacier
![Page 35: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/35.jpg)
Receding Athabasca Glacier in Alberta
It has receded 1.5 km since 1843.
![Page 36: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/36.jpg)
![Page 37: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/37.jpg)
What does this mean?Ocean waters may rise
Flood riversIf they disappear, rivers may dry up.
![Page 38: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/38.jpg)
WatershedsThe area of land with water
that drains into a body of water such as a river, pond, lake or ocean.
There may be many smaller basins within a larger basin.
6.Drainage Basins
![Page 39: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/39.jpg)
A divide separates one basin from another.
For example: The Continental Divide
![Page 40: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/40.jpg)
Canadian Drainage Basins
![Page 41: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/41.jpg)
Drainage basins close to home are Labrador Sea, & Gulf Of St. Lawrence
![Page 42: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/42.jpg)
6 Major Drainage Basins in NL1. Labrador Sea 2. Gulf of St. Lawrence3. West Coast Gulf of St.
Lawrence4. South Coast Gulf of St.
Lawrence5. Atlantic Ocean Avalon
Peninsula6. Atlantic Ocean North-east
Coast
![Page 43: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/43.jpg)
One Component Affects Another
Salinity :affects the types of organisms that can survive in an area. Eg. Dead Sea
![Page 44: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/44.jpg)
Temperature :affects the amount of dissolved oxygen in water. Ex. The higher the temp. the more oxygen.
![Page 45: Grade 8 Science](https://reader031.fdocuments.us/reader031/viewer/2022020920/568163ff550346895dd59f1b/html5/thumbnails/45.jpg)
The convergence of the Labrador Current and the Gulf Stream Current (place where they meet)influences productivity of the Grand Banks (more fish there), the movement of icebergs, and migration of capelin and whales.