Technology Enables Us To Explore Our Earth The Land and the Oceans

Technology EARTH

Using Technology GPS Remote Sensing GIS Electromagnetic Spectrum Reflectance Curves Reflectance Curves Ground Truthing Buoys

Buoys are Buoyant

Buoys are used to help monitor large bodies of water on the Earth. They are often computerized and transmit data about ocean temperatures, wind patterns, currents and air temperature.

What Color is Light?

Electromagnetic Spectrum Shows Waves of Energy

Reflectance Curves This is simple a “GRAPH” that shows how a type of matter reflects visible, infrared (heat) or other wavelenghts of light. An upward curve indicates a lot of light is reflected. A downward curve show that the wavelength is absorbed.

Spectral Analysis The study of the reflectance of objects or substances on Earth using Satellite Imagery Electromagnetic Spectrum

Pictures that show satellite images and rely on color to represent data

Satellite

Using Satellites Helps In Monitoring the Earth Differences in soil types Algae – floating on top of water Distribution of plants (vegetation) Urban sprawl (growth of cities) Changes in deserts, forests and other large areas on the Earth

Global Positioning System

A GPS uses satellites to pinpoint locations on Earth. A GPS unit on Earth communicates with three or more satellites then calculates the latitude, longitude and elevation of the GPS and transmits the that position back to the unit.

Technology Enables Us to Explore the Ocean’s Depths

Alvin - submercible

Underwater Research

Robots

Jason – deep ocean vessel

SONAR Acronym for: Sound Navigation and Ranging Sonar is a method of determining the depth of the ocean using echoes. It is also used to find “fish”.

Technology and the Hydrosphere SONAR – COACH – page 144

Sonar

Remote Sensing A method of seeing what is beneath or on the surface of the ground and ocean It enables us to collect information about an area without visiting the area. Satellite photographs are a type of Remote Sensing

How Remote Sensing Works

Technology helps us to explore our Hydrosphere and the land on Earth “Remote Sensing” Data can help scientists understand: About Food Webs How nutrients are distributed How sediments spread in water Help scientist observe and predict climate changes Predict or monitor “EL Nino” –See patterns of changes in surface currents and temperatures

Ground Truthing A method of verifying the truth of a satellite images This is done by visiting the area in person

Ground Truthing – involves scientists visiting an area and looking at maps that have been prepared by satellites and be able to confirm that their maps match what was seen in the photograph and that actual terrain of the area.

Geographic – COACH – page 164 Information System GIS- Mapmaking software - Layers Maps the location of a watershed Show measures of controlling water quality Water temperature pH and dissolved oxygen Identify pollutants that are near the area

Using Technology GPS Remote Sensing GIS Electromagnetic Spectrum Topographic Map Ground Truthing Studying an area without visiting the area in person Software that shows layers of maps

Topographic Mapping

Topographic Maps The study of Earth’s natural and artifical features by surveying and mapping the land

What is a Topographic Map? In contrast to most maps, a topographic map shows the shape of the Earth’s surface by using contour lines. Topographic maps are used to show elevation.

Contour lines are imaginary lines that join points of equal elevation above or below sea level. They never intersect or meet.

Let’s take a walk up a hill!

We’re now at an elevation of 100 meters. 100m

Let’s keep going! 100m

Now we’re at 200m. 100m 200m

Shall we march on? 100m 200m

We’ve made it to 300m! 100m 200m 300m

On to the peak! 100m 200m 300m

We’re on the peak, but what’s our elevation? 100m 200m 300m

Any ideas? 100m 200m 300m Let’s add contour lines for every 50 meters and see if that helps.

100m 200m 300m We know that we are above 350m, but less than 400m. 50m 150m 250m 350m

100m 200m 300m Let’s head down the hill, it’s getting late! 50m 150m 250m 350m

100m 200m 300m Now what’s our elevation? 50m 150m 250m 350m If you said somewhere between 200m and 250m you are right!

100m 200m 300m Let’s try this again! 50m 150m 250m 350m

100m 200m 300m What’s our elevation now? 50m 150m 250m 350m If you said 50m or just under, you’re right!

Let’s now look at the same hill, but the way we might see it from an airplane!

Each color change represents a 50 meter increase.

Now, let’s try the same hike! Our elevation is 0 meters.

Now what is our elevation?

If you said more than 150 meters, but less than 200 meters your right!

Let’s go a little higher.

Think you know our elevation now? More than 300meters But less than 350meters

If we were standing on the peak, what would be our elevation? More than 350 meters, less than 400 meters

Let’s head down hill.

Know our elevation?

More than 100 meters, less than 150 meters

Contour lines are lines that connect points that are of the same elevation. They show the exact elevation, the shape of the land, and the steepness of the land’s slope. Contour lines never touch or cross.

Topographic Map

What is a contour interval? A contour interval is the difference in elevation between two contour lines that are side by side. Remember that a contour interval is not the distance between the two lines – to get the distance you need to use the map scale.

What if my contour lines are close together? If the contour lines are close together, then that indicates that area has a steep slope.

What if my contour lines are far apart? If the contour lines are far apart, then that indicates the land has a gentle slope (low slope).

What do the dark colored contour lines mean? The dark colored contour lines represent every fifth contour line to make it easier to read the map.

Let’s see what you know. 400m 800m 1000m 1200m A B C D E F 600m

Grab a piece of paper and write your answers to the following questions. Ready?

1. Could the elevation at the peak (B) be 1410 meters? 400m 800m 1000m 1200m A B C D E F 600m

2. What is the elevation at (E)? 400m 800m 1000m 1200m A B C D E F 600m

1. No :The elevation must be under 1400 meters, but over 1300 meters. 2. about 400 meters

3.What is the elevation difference between (A) and (B)? 400m 800m 1000m 1200m A B C D E F 600m

3. (A) is probably close to the 750 meter line, (B) is above 1300 meters. The difference between the two would probably be 650 to 700 meters.

4. Could the elevation at (F) be 417 meters? 400m 800m 1000m 1200m A B C D E F 600m

5. If you walked a straight line from (D) to (C) would you walk over a ridge or down a valley? 400m 800m 1000m 1200m A B C D E F 600m

4. No: It must be more than 700 meters and less than 800 meters. 5. Down a valley: If the contour lines point up the slope it’s a valley, if they point down the slope it’s a ridge.

6.Just looking at the map, would it be easier to head down from the peak going East, or going North? 400m 800m 1000m 1200m A B C D E F 600m E N S W

6. East: When contour lines are close together that means there is a steep slope, the further apart the lines, the more gentile the slope and therefore an easier walk! Go east!

Using Technology 7

GPS Remote Sensing GIS Electromagnetic Spectrum Reflectance Curves Reflectance Curves Ground Truthing Buoys