Dr. Hansen's Research

The main purpose of research at Hope College is the training of the next generation of scientists.  In the Geological and Environmental Sciences Department we do this by inviting students into our laboratories early in their undergraduate careers and collaborating with them for several years on significant publishable research.  My students generally present the results of their research at national meetings like the annual meetings of the  Geological Society of America , The International Association of Great Lakes Research, and the Association of American Geographers or regional meetings like those of the Michigan Space Grant Consortium and the Michigan Academy of Science, Arts, and Letters (list of student research presentations over the last 3 years - link).  They also publish the results of their work in internationally recognizable journals such as Geomorphology, The Holocene and Lithos. 

Dune Research

Since the year 2000 the main focus of my undergraduate research program has been the coastal sand dunes along the eastern shore of Lake Michigan.  These make up the largest collection of freshwater coastal dunes in the world.  Our studies of these dunes give us valuable information that will help us manage and protect them and yields important insights into both the development of coastal dunes in general and climate change in Michigan over the last 5000 years. Our coastal dune research falls into several different topics.

CONTEMPORARY DUNE PROCESSES

Brian Yurk checking sand traps at the crest of a large parabolic dune (150 feet tall) southwest of Holland. This research concentrates on the transportation and deposition of sand on large actively migrating dunes. Student research projects have focused on:

• How the pattern of sand transportation and deposition is influenced by seasonal changes in temperature and wind velocity.


• How the depositional patterns are influenced by the steering of wind by the topography of the dunes.


• How the deposition of sand influences the vegetation patterns on the slopes of dunes. The principal Hope College students involved in this work have been Brian Yurk, Katie Sherron and Ryan Zietlow. Deanna vanDijk from Calvin College and Suzanne DeVries-Zimmerman from Hope College have also collaborated on this work.

HISTORY OF DUNE COMPLEXES

In order to create a history of the Lake Michigan dune complex we need to know when the dunes began forming, the timing of the various episodes of dune growth and migration, the ways in which these events changed the geometry and position of the dunes. Our chief clues in answering these questions come from the study of dune paleosols. Paleosols are old soils that formed on the surface of a dunea during periods in which the dune was not migrating or growing. These soils are buried by sand during episodes of new dune growth and migration and are later exposed by erosion. By mapping theses paleosols we can obtain information on the position and geometry of the dunes earlier in their history, and by obtaining radiocarbon ages from plant remains in the paleosols we can get information about the timing of periods of dune stability and mobility.We also obtain information on the history of the dunes by mapping the current dune surfaces and determining their ages using a technique called optically stimulated luminescence. Students doing this work have tended to work in teams that concentrate on the history of individual dune complexes. By putting these individual projects together we have developed a general history of the coastal dune complexes along the southeastern shore of Lake Michigan. The principal Hope College students involved in this work have been:

1. Will Weiss and Kevin Woloszyn (Indiana Dunes National Lakeshore)
2. Martin VanOort (Van Buren State Park)
3. Emily Timmons, Sean Derby and Ryan Zietlow (Warren Dunes and P.J. Hoffmaster State Parks)
4. Martin VanOort and Ben Hansen (dunes southwest of Holland)
5. Michelle Knapman and Dan Miller (P.J. Hoffmaster State Park)

Alan Arbogast of Michigan State University and Mark Bateman of Sheffield Centre for International Drylands Research have collaborated with us on this work.

SEDIMENTARY STRUCTURES IN DUNES

The arrangement of different kinds of sedimentary layers in dunes (sedimentary structures) can give information about the conditions under which the dune sands were deposited. Our work on sedimentary structures in the Lake Michigan dunes have concentrated on the origin of pinstripes: thin black layers made up of relatively small dark mineral grains. The goals of these studies have been twofold: to understand how pinstripes form and to trace the sand grains in these pinstripes to their original source.

Principal Hope College Students involved in various aspects of this research have been Kieko Kito, Anna Davis, Kristin McPhee, Eric Johnson and Brad Johnson. We have collaborated with Karen Halvholm of the University of Wisconsin St. Claire on this project and have received invaluable advice from John Barwis (retired from the Royal Dutch Shell Corporation)

SEDIMENT CORES FROM SMALL LAKES WITHIN DUNE COMPLESES

Sediments collect continuously at the bottom of small lakes within dune complexes and sediment cores taken from the bottom of these lakes contain a record of environmental changes in the surrounding dunes. We began looking at these sediments for clues to dune history three years ago and are still learning how to "read" this record. So far we have been able to use variations in the concentration of windblown sand in these cores to construct high-resolution chronologies of dune mobility and stability extending back five thousand years. We have also examined diatom fossils, pollen and minerals in the cores for clues to environmental change in the surrounding dunes. The principal Hope College students who have been involved in this research are:

1. Emily Timmons and Sarah Dean (analysis of windblown sand)
2. Trevor Daly (analysis of diatoms)
3. Elliot Eisamen and Kimberly Jongsma (analysis of pollen )
4. Carrie Thomason and Amanda Brisbin (mineralogical analysis).
   Tim Fisher of the University of Toledo has collaborated with us on this work.

RESEARCH IN METAMORPHIC PETROLOGY

Metamorphism is the process by which rocks are transformed by heat, pressure and chemically active fluids in the interior of the Earth. Up until eight years ago understanding the role of fluids in metamorphism was the main focus of my research and I still continue to work on the problem in collaboration with Dan Harlov at the GeoForschungsZentrum, Potsdam, Germany. Recent student projects in metamorphic petrology have included:

1. Khurram Ahmend's examination of trace element chemistry of biotites in metamorphic rocks from south India.
2. Carrie Thomason's study of partial melting in high temperature metamorphic rocks from south India.
3. Jesse Reimink's study of fluid induced chemical and mineralogical changes in metamorphosed conglomerates from the Keweenaw Peninsula.

We are gearing up for a study of metamorphic rocks in southwestern Halland Province, Sweden in collaboration with Arancha Pinan-Llamas from Hope College, Leif Johansson from Lund University Sweden and Dan Harlov from the GeoForwschungsZentrum, Potsdam

RESEARCH IN THE COMING YEAR

In May and early June 2008 Dr. Pinan-Llamas and I plan to work with two Hope College students mapping metamorphic rocks and structures in Halland, Province Sweden. I also plan to work with several other students on a study of the history of coastal dunes along the western coast of Lake Michigan. This will involve mapping paleosols,and modern dune surfaces and examining sediment cores from small lakes behind the dunes.

Abstracts Based on Presentations by Hope College Students at Professional Meetings 2002-2007 Presenter's names are underlined, undergraduate student coauthors in bold.