From sand seas to sand stones: Global data sets and virtual

exploration in the classroom using

Google Earthby Les Hasbargen

SUNY Oneonta2014

Key Themes: Inquiry-based exercise

1. Students explore the world! (and planets…)2. Students measure landforms3. Students construct hypotheses and test

them--if data are available

● For sand seas, students discover size, location, and shape

● Initial observations lead to questions about stratigraphy and sandstone bodies from the past...

Key Themes for Student Projects

In this exercise, students:● Measure dunes and sand seas● Attempt to decipher wind direction from

shape● Tie dune shape and size to cross

stratification (this is an attempt! )● Look at stratigraphy in regional cross

stratified sandstones (if imagery is available)● Interpret the setting for the sand body

Learning outcomes/goals

• Learn how to use spatial data to measure geologic features

• Develop critical thinking skills in comparing modern to past dune environments

• Develop writing and report presentation skills• Develop skills in collaborative investigation

Enter Google Earth...

● Global (and planetary) aerial imagery and topography

● Students do need some training with navigation, storage of user-created data, and point-line-area creation in GE

● Students learn how to use screen captures and develop annotation skills

● If there’s internet, pull up Google Earth...

Mongolia

● Can one determine thickness of the sand sea?● Dune height can be measured.● If cross-stratification scales with dune size, then x-strat is measurable

○ slip face slope = bounding surface? ○ set thickness scale with dune height?○ dune asymmetry set by wind direction○ foreset dip direction

Namibia

Note that it may take a minute or two for the higher resolution topography to be accessed--you can tell when dunes become visible

How might x-strat vary around this sand sea?Can one use Hadley cell circulation to model wind patterns?Where is the sand coming from?

Afghanistan

What kind of cross stratification here?

Taklimakan DesertWhat is the wind direction, based on dune asymmetry?

Taklimakan Desert, north-south profile

Note that wedge-shaped deposit, and ability of sand to “climb to new heights”

Taklimakan Desert, west-east profileNote the variation in dune sizeNote the wedge-shaped mass of sand

Cross stratified sandstones in the US

● Glen Canyon Groupo Navajo sandstoneo Kayenta formationo Wingate formation

● Locationso Zion Canyono Glen Canyono Grand Canyono Valley of Fire

Background for Dunes and Sandstones

● http://sed.utah.edu/Navajo.htm, from National Park Service, about the Navajo SS

● http://offices.colgate.edu/bselleck/Geology120/NavajoB.pdf, very nice summary with maps of SS extent in the Jurassic

● Current research list: Query results from Astrophysics Database

● Recent experimental dune growth● Dave Rubin

o http://www.nature.com/ngeo/journal/v2/n9/abs/ngeo610.html o http://walrus.wr.usgs.gov/seds/bedforms/animation.html

● Wikipedia: http://en.wikipedia.org/wiki/Dune

More Online Geology

● Utah Geologic Map, 1:500K: needs to be converted to online searchable map

● Geolex (USGS)● I couldn’t find an easy, sortable, searchable

geologic map online (and problems with size for a Fusion table)

● Take advantage of photos in Google Earth

Student created products

● Topographic profiles of dune seas, and eroded cross sections of Navajo/Wingate SS showing thickness

● Screen captures of mapped extent● Verbal descriptions of sand sea geometry and dune shape● Statement about slip face orientation and dominant wind flow

direction● Statement about sediment sources for the dune field● Statement about conditions of formation for Glen Canyon

Group (Navajo ss, Kayenta formation, Wingate formation)

Assessment

● The topographic profiles need to have descriptive titles with location; annotation on the profile and/or comments in a caption which describe and interpret the profile.

● Sand sea descriptions should provide a sense of the extent and rough estimate of thickness, along with the geographic setting for the dune region; an estimate of dominant wind direction; and an identification of the potential sources of the sand.

● Data collection and analysis can be ranked according to excellent, good, fair, poor, unacceptable.

● Summarization can be ranked according to excellent, good, fair, poor, unacceptable.

Work in Progress! I could use some sedimentologic advice on this one!

● Better imagery of cross stratified cliffs would make this project much more feasible

● Imagery should have a viewing direction and approximate scale

● An online resource for on the ground imagery would be ideal, either in Google Earth, or as a Fusion Table (looks like Google Maps…)

● A clickable, searchable, filterable online geologic map of Utah would also allow students to discover the extents of sandstone deposits on their own

And a plug for one more thing…

See my teaching activity for this workshop called

Meander Migration in the Amazon

In it, you’ll find links to Google’s Earth Engine, with time series of Landsat imagery since 1984

http://serc.carleton.edu/NAGTWorkshops/sedimentary/SGP2014/activities/85513.html