This chapter is most appropriate for students in grades 9 - 16.
After completing this chapter, students will be able to:
- explain how technology has been used through history to explore Earth's coastlines and the seafloor;
- download, install, and use GeoMapApp for geospatial data analysis;
- generate and interpret visualizations of seafloor depth data;
- record, graph, and analyze geospatial information; and
- hypothesize about the formation of observed seafloor features.
High school students are usually familiar with topographic maps that show elevations ranging from zero (sea level) upward. They have also been introduced to the basic concepts of plate tectonics. However, they have generally had little experience exploring the topography of the seafloor.
The bathymetric images in GeoMapApp are not satellite images or photographs, as many users may initially assume. Rather, they represent sonar data (depth measurements) that are compiled by computer software into a continuous grid. The sonar data are collected by oceanographic research ships. Displaying the grid of measurements according to a color code helps us interpret the imagery as the topography we would see if the water were removed from the ocean basins. You can find out more about the data collected by and used for marine research at the Marine Geoscience Data System site.
Instructors may want to preface this activity by demonstrating how we can map something which we cannot see. Prepare a box with a familiar object attached to the inside bottom and a wide grid of small holes in the top. Probe the holes with a "sonar stick" (chopstick or other thin wooden stick that has been calibrated with color) to determine the depths to the bottom of the box across the grid. Construct a map using color to indicate the shape of the object. Replace the box top with one that has a finer grid of holes and repeat. This will show that taking more measurements will result in a more detailed map.
The following questions can be used to elicit students' current understandings before the activity.
- How deep do you think the ocean is?
- Do you know how to convert feet to meters?
- Describe what you think the seafloor looks like. Sketch a picture.
- How do you think experts in oceanography know about the seafloor?
- Why might the depth of the oceans and the shape of the seafloor be of interest to humans?
The chapter culminates with a collaborative project on contour mapping. The quality of the final project depends on:
- initial group work - accuracy of collecting data from GeoMapApp and creating a profile graph;
- whole class collaboration - translating data from the graphs into one large grid;
- individual and group work using GeopMapApp to verify the product;
- individual analyses of maps; and
- group presentation of analyses with justified reasoning.
The following National Science Education Standards are supported by this chapter:
- 12ASI1.1 Identify questions and concepts that guide scientific investigations.
- 12ASI1.3 Use technology and mathematics to improve investigations and communications.
- 12DESS3.3 Interactions among the solid Earth, the oceans, the atmosphere, and organisms have resulted in the ongoing evolution of the Earth system.
The following U.S. National Geography Standards are supported by this chapter:
The World in Spatial Terms
1. How to use maps and other geographic representations, tools, and technologies to acquire, process, and report information from a spatial perspective.
2. How to use mental maps to organize information about people, places, and environments in a spatial context.
3. How to analyze the spatial organization of people, places, and environments on Earth's surface.
7. The physical processes that shape the patterns of Earth's surface
Project 2061: Benchmarks
- Scientific investigations are conducted for different reasons, including to explore new phenomena, to check on previous results, to test how well a theory predicts, and to compare different theories.
- Science disciplines differ from one another in what is studied, techniques used, and outcomes sought, but they share a common purpose and philosophy, and all are part of the same scientific enterprise.
- Technological problems often create a demand for new scientific knowledge, and new technologies make it possible for scientists to extend their research in new ways or to undertake entirely new lines of research. The very availability of new technology itself often sparks scientific advances.
- Mathematics, creativity, logic and originality are all needed to improve technology.
Approximately 3 full class periods.
Ridge 2000 Program: Exploring the links between Planetary Renewal and Life in the Deep OceanR2K
MARGINS: A project to understand the complex interplay of processes that govern the evolution of continental margins.
NOAA's Ocean Explorers Seafloor Mapping SiteSea Floor Mapping
Data Acquisition, Processing, Interpretation, and ArchivingUSGS Sea Floor Mapping Site
The Physics of SoundNOAA - Ocean Explorer