7.3 Oceanography 7.4 Glaciers 7.5 Wind 7.6 Glavity Self-paced Tutorial: Topic 7.3-7.6 Surfaces...

7.3 Oceanography7.4 Glaciers7.5 Wind 7.6 Glavity

Self-paced Tutorial: Topic 7.3-7.6Surfaces Processes

Image source:http://photography.nationalgeographic.com/photography/photos/ocean-soul/#/southern-right-whale-ocean-soul-skerry_43469_600x450.jpg

Topic 7.3 Oceanography Oceanography is defined as the study of the world’s oceans. •Oceans cover 75% of Earth’s surface•Average depth = 3-4 km

• map ocean depths

• study the ocean floor

• study ocean currents

• study glaciers and climate change

• search for valuable resources in the ocean floor

• engineer new sources of renewable energy with tides and currents

• study marine plants and animals

• study ocean’s effect on climates

Images source:http://water.thinkaboutit.eu/think5/post/water_love.html

An oceanographer can:

Continental Shelf

Continental Slope

Continental Rise

Abyssal Plain

Use this diagram to label the diagramin your report sheet.

Surface Ocean Currents (ESRT page 4)

Two Types of Ocean Currents1. Surface Currents are caused by

planetary winds:•can vary in width, depth and speed•consist of the uppermost 400 meters•form circular currents called GYRES

2. Deep Ocean Currents are caused by differences in density created by salinity and temperature differences.

Two Types of Ocean Currents1. Surface Currents are caused by

planetary winds:•can vary in width, depth and speed•consist of the uppermost 400 meters•can form circular currents called GYRES

Gyres – are surface currents that flow in circular pattern in the world’s major ocean basins

Two Types of Ocean Currents2. Deep Ocean Currents are caused by

differences in density created by salinity and temperature differences.

http://www.youtube.com/watch?v=UuGrBhK2c7U

“The Great Ocean Conveyor Belt” not only moves amazing amounts of water all over the globe but has profound effects on the global climate.Click to watch the video and learn HOW.

Deep Ocean

Currents

This 3-D image shows how the ocean currents change depth and temperature as they move around the globe.

C. Erosion from Oceans

Longshore Transport (AKA Drift) is the movement of sand down the beach because waves hit the beach at an angle.

Longshore Drift (current)

Describe how long-shore currents move sediment? The waves hit the beach at angle so sand moves at the same angle. As the wave “washes” back to the ocean, the sand move back down but straight down.

With the next wave, sand is moved down the beach at the same angle the waves approaches and continues to move the sand along the beach. The dotted line arrow on the beach show the movement of sand.

Longshore DriftClick on either “add groins” or “add jetties” and watch where sediment is deposited and eroded. Often this is on the regents exam.

• Sand bars – a bar of sand deposited by longshore currents that move parallel to the shore

• Sand Spits – a type of sand bar, which begins to stretch across a bay.

• Baymouth bar – a type of sandbar that stretch across a bay

D. Deposition from Oceans:

• Barrier Islands – a type of sand bar that is unattached to the shoreline

If you lived in Kingston, NY 10,000 years ago, you wouldn’t know what the ground looked like because you would stand on a continental glacier 1 mile thick!

Click on the link below to view a video clip on glaciers:

http://www.redorbit.com/news/video/education_1/1112766120/what-is-a-glacier/

Two main types of glaciers

1. Ice sheet (continental)- huge, relatively flat masses of snow and ice on land.

2. Moutain or valley Glaciers - long & narrow; confined to

valleys (look like rivers of ice).

B. How do glaciers form and move?A glacier moves because gravity is pulling it. It moves

forward (advances) when more snow is accumulating than is ablating (means loss of ice due to melting).

A glacier moves backward (retreats) when ablation (melting) is more than accumulation.

C. How do glaciers erode sediments?

They

PLUCK

them! Click on both buttons and watch “insets”.

How do glaciers deposit sediments?Watch the “inset movie B” and notice

how the glacier deposits sediments.

What features form from glaciers?Notice the “U”

shape of the valleys and the bowl shaped depressions called cirques. Horns are the pryamid-like shape of mountain peaks eroded by glaciers.

What features form from glaciers?Notice the 2 moraines (recessional and terminal)

that are linear deposits of UNSORTED sediments. The drumlin field is an area where the glacier drops mounds of sediment and then moves over it creating a “tear drop” shape that always points

in the direction the glacier was moving forward.

NY’s prominent glacial feature

7.5 Wind

Click on both buttons and watch “insets”.

A. Wind Erosion: the stronger the wind, the larger (and more) sediments can be transported. However, relatively small particles can be moved by wind.

B. Wind Abrasion:In dry climates, wind abrasion can severely alter the appearance of the landscape. As sand is carried by wind against other rocks, it abrades the rock and can form some really cool structures!

This is Bryce National Park in Utah. These hoodoos are a result of wind abrasion.

C. Wind Deposition:Generally, as the wind speed decreases, the sediments get deposited. Sand dunes are a result of wind deposition.

Image source:http://mamontoff.org/SCIENCE%20deposition%20wind.jpg

Image source:http://www.photography-match.com/views/images/gallery/Sand_Dunes_and_Acacia_Tree_Namib_Desert_Namibia.jpg

7.6 GravityA. Gravity gets the assist:Gravity is the primary force behind most

erosion because its gravity that causes water and glaciers to move. Click this link to watch a time lapse of glacial movement:http://www.youtube.com/watch?v=89sOW-FzolI

7.6 GravityB. Gravity Erosion:Gravity also transports sediments by itself. Rocks that fall from a cliff and landslides are types of erosion by gravity.

7.6 Gravity1st View this video on the mudslide in Oso, Washington 2014.http://www.youtube.com/watch?v=oXp72dZdqu4

2nd Follow this link and view the before and after images: http://www.abc.net.au/news/2014-03-26/washington-mudslide/5346460

The houses outlined in red no longer exist because they were destroyed and buried by the mudslide.

Image source:http://media.komonews.com/images/140401_Washington_Mudslide_xx_18.jpg

QuestionsView this video on the “great pacific garbage patch”.http://www.youtube.com/watch?v=y5y1W5xduiE