You Can’t Get There From Here…Or Can You?
Focus: How are charts, maps and Geographic Information Systems used in ocean exploration today and in the 1800’s?
Grade Level: 6-12
Focus Questions: How are maps, charts, and GIS similar and different? What is a Geographic Information System and how can it be used to understand ocean exploration today, and in the past?
Students will compare the kinds of mapping technologies used in the 19th century and today.
Students will understand the difference between maps and charts.
Several examples of modern nautical charts
Several examples of modern maps (road map, etc.)
Printouts of one or more charts from HMS Challenger website
Teacher Reference Sheet on the differences between maps and charts
Audio/Visual Materials: Computer
Teaching Time: One or two 45-minute periods
Seating Arrangement: Individually or in groups
Maximum Number of Students: None
Keywords: HMS Challenger
Geographic Information Systems
Note to Teachers:
This lesson is one of a series collectively called "The New Challenger Series." The series can be found online at http://www.coexploration.org/hmschallenger.
The historic voyage of the British ship HMS Challenger, conducted between 1872-1876, is considered to be the first expedition undertaken specifically to conduct oceanographic research. HMS Challenger had the specific assignment from the British government “to investigate the physical and biological conditions of the great Ocean Basins.” Five scientists, one artist, 23 officers and 243 sailors comprised the Challenger’s all-male crew. Their 3 ½-year around-the-globe voyage covered almost 69,000 nautical miles and gathered data on temperature, currents, water chemistry, marine organisms, and bottom deposits at 362 oceanographic stations. The scientific results of the voyage were published in a 50-volume, 29,500-page report that took 23 years to compile, and form much of the basis of modern marine biology.
Being true explorers in the 19th century, the crew did not have charts of the ocean when they began their voyage. Challenger’s crew created more than forty charts as they traveled around the world, taking soundings, or depth measurements along with samples of the ocean floor. The charts they created were generally accurate about the composition of the ocean floor, but could not give more than general information about the detailed topography.
Today, we have nautical charts that show water depth, navigational aids such as markers and buoys, the shoreline of adjacent land, topographic features, and other information. Charts serve as a work area on which the navigator plots courses, determines position at sea, and ascertains the position of a ship in relationship to the surrounding area. A navigator uses charts to avoid hazards and arrive safely at a destination.
Maps are visual representations of the spatial locations of natural and man-made features (e.g., rivers, coastlines, roadways, mountains, pizza parlors, animal habitat) on the earth’s surface, including the ocean floor. They can come in many forms – printed on easily-transported paper, molded into three dimensional physical forms, displayed on computer screens, etc. They can also be quite beautiful – reflecting the ingenious ways features can be represented as symbols, colors, shading, etc. and the aesthetic elements of layout, proportion, balance and typeface. This is the art of map-making. Modern maps are compiled from a wide variety of data sources – aerial photographs, satellite imaging, ground-based surveys, government and business records that include locations, and many other sources.
Geographic Information Systems
A recent innovation in mapping is the development of Geographic Information Systems (GIS). This computer software stores spatial data in a database management system that preserves all the spatial relationships among the data.
As a GIS user, the first thing that is visible when the computer is turned on is a blank white screen. This blank GIS world should not be seen as empty space, but as the surface of the Earth, with all of its features and various phenomena "turned off." Earth’s features can be carefully added to this digital world, one at a time, and stacked into separate but overlapping layers. The unique analytical power of a GIS comes from its ability to find relationships between these separate but overlapping layers of information. In ocean exploration, a GIS user manages unique spatial information produced by a wide variety of ocean-sensing instruments, such as satellites, buoys, sonar, submersibles, traps, trawls, underwater cameras, and other devices, until they can be combined to form a multilayered reconstruction of geographic reality.
GIS can also be used to better understand the Challenger expedition. For example, the site data from Challenger (e.g., latitude, longitude, depth, sea surface temperature, bottom type) at all of the 362 sample locations visited can be entered into a GIS. Then the data can be displayed in radically new ways, combined with other data collected during the expedition and with contemporary data, and spatial analyses can be performed that help the user understand the original data better.
1. Either have students visit http://www.coexploration.org/hmschallenger for background on the Challenger expedition, or refer to the Background section above. Ask students how they think the first charts of the ocean were made.
2. Hand out copies of the H.M.S. Challenger chart. Many other charts can be found at
http://www.hmschallenger.org/1885narrative/Charts.html Pass around a few examples or copies of modern nautical charts. (If these are not easily available, visit http://mapserver.maptech.com/bp/mapserver/index.cfm). Ask students to list the differences in data presented in the Challenger chart and a modern chart.
3. Hand out or circulate several different types of maps (road map, shopping mall map etc.) Ask students to write a one or two paragraphs on how they think these maps differ from the nautical charts. Students could also work in small groups to then create a classroom document "Difference Between Maps and Charts," similar to the Teacher Reference sheet. Discuss the value of maps, and how they can help answer questions such as: Where are we? Where is the place we are looking for? How do we get there? How long will it take? How can we recognize spatial patterns, relationships and trends in the data I am collecting?
4. Discuss with students the concept of GIS. Either print and hand out the following web page or have students visit the site online for an introduction to GIS in ocean mapping:
5. Working in groups, have students design a poster that depicts situations where a GIS map may be helpful in ocean exploration, and what kinds of data layers could be presented. Give them examples such as: They are an ocean drilling team researching the best place to drill for oil in the ocean, or they are scientists trying to decide the best location for an underwater monitoring buoy, or they are trying to map an underwater mountain and trying to visualize what it looks like.
NOTE: The College of Exploration has entered the Challenger data into a GIS, and is working on a way to make it usable on the web. Please note that users will need the ArcView software in order to use the data effectively. Please check the College of Exploration’s website for updates on the availability of the GIS data. (http://www.coexploration.org/hmschallenger)
Ask students to design an updated Challenger cruise plan using either nautical charts or GIS (if available).
The "Me" Connection
Have students draw and illustrate a map of their neighborhood/street with a key. They should pick a main street in town and then draw the map to their house and include a key and compass rose. This activity also works well as a warm up before the lesson, where students can do the assignment as homework, then compare their maps in class the next day.
Connections to Other Subjects: History, Social Studies, Geography
For a lesson on the History of Cartography, visit:
Have students explore the discovery of the “Challenger Deep” (also known as the Marianas Trench in the Pacific). Refer them to the following website: http://www.coexploration.org/hmschallenger
NOAA Ocean Explorer Website
College of Exploration's HMS Challenger website - Charts section
University of Kansas Natural History Museum
History of Mapmaking
The GIS 2 GPS Portal / Resources For Educators & Students
National Science Education Standards
Content Standard A: Science As Inquiry
Content Standard E: Science and Technology
Content Standard F: Science in Personal and Social Perspectives
Content Standard G: History and Nature of Science
Acknowledgments: This lesson was created by Melissa Ryan for the College of Exploration in Potomac Falls, Virginia, with contributions from Scott Carley, and Dr. David Bossard.
Teacher Reference Sheet
What Is the Difference Between a Chart and a Map?
(From NOAA Office of Coast Survey)
A chart, especially a nautical chart, has special unique characteristics including a very detailed and accurate representation of the coastline, which takes into account varying tidal levels and water forms, critical to a navigator.
A map, on the other hand, emphasizes land forms, including the representation of relief, with shoreline represented as an approximate delineation usually at mean sea level.
A chart is a working document. It is used to plot courses for navigators to follow in order to transit a certain area It takes into account special conditions required for one's vessel, such as draft, bottom clearance, wrecks and obstructions which can be hazardous. Way points are identified to indicate relative position and points at which specific maneuver such as changing courses, must be performed.
A map on the other hand is a static document which serves as a reference guide. A map is not, and can not be used to plot a course. Rather it provides a predetermined course, usually a road, path, etc., to be followed. Special consideration for the type of vehicle is rarely a consideration. Further, maps provide predetermined points-road intersections-to allow one a choice to change to another predetermined direction.
Charts provide detailed information on the area beneath the water surface, normally not visible to the naked eye, which can and is very critical for the safe and efficient navigation.
Maps merely indicate a surface path providing no information of the condition of the road. For instance a map will not provide information on whether the road is under repair (except when it is a new road) or how many pot holes or other obstructions it may contain. However the driver is able to make a visual assessment of such conditions.
H.M.S. Challenger Chart