Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Slicks
Name: Marty G.
Status: Educator
Age: 40s
Location: N/A
Country: N/A
Date: N/A 


Question:
What causes the "slicks" that sometimes form on a large, irregular body of water with flow (river or estuary, for example)? The slick appears under certain wind conditions as a linear, with-the-current calm region on an otherwise more ripply surface. (I'm guessing that a very thin layer of oil or oil-like material is stretched along the surface, decreasing the wind's purchase on the water.)



Replies:
Your guess is probably correct. The "slicks" are visible because of light interference because the film thickness is of the order of the wavelength of visible light -- 400-700 nanometers. The source could be from agricultural runoff, oil contamination or even a "natural" source such as the sap from evergreens. The colors of the slick will move and swirl with the current as the moving water changes the thickness of the film.

Vince Calder



Click here to return to the Environmental and Earth Science Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory