Karst Hydrogeology of the Yucatan Peninsula

Alumnus Luis Marin (MS 1986) organized and led the field trip that served as the capstone of a hydrogeology graduate seminar (Karst Hydrogeology of the Yucatan Peninsula) of the preceding fall semester. The field trip greatly enhanced all that we read about in the seminar portion of the course. We are especially grateful to those who contributed to the Hydro Fund and other department funds, which provided financial support for the trip.

During spring break 2006, a group of intrepid Geobadgers made their way across Mexico’s Yucatan Peninsula on a field trip exploring the region’s unique hydrogeology. The group included Professor Jean Bahr and Professor Emeritus Carl Bowser and grad students Jeff Wilcox, Heidi Crosby, Rachel Greve, Mike Cobb, Jonathon Carter, Chris Muffels, Chris Lowry, Laura Craig, and Jeff Schneider (GLE)

Hydro group
Group at the Great Pyramid overlooking Uxmal. Click for a description.

Karstification of the Yucatan Peninsula has progressed to the point that its northern half is devoid of surface drainage. Sinkholes—known as cenotes—are the most prominent karst features and serve as the sole water supply for many communities.

In our travels we encountered a variety of cenote forms. The maturity of a cenote could be determined by the extent to which its ceiling remained intact. At one location, we visited three cenotes aligned along a joint that spanned the development spectrum. At another series of cenotes, we snorkeled through the maze of passageways of a submerged cave system, complete with stalactites and stalagmites.

At the ancient Mayan cities of Uxmal, Chichen Itza and Tulum we learned about the centrality of water in the Mayan society. Chichen Itza was established in close proximity to two cenotes, which became important features of their religion as they were believed to be portals to the underworld. Unlike Chichen Itza, Uxmal and Tulum did not have the luxury of cenotes close at hand. The water storage system of Uxmal was quite impressive and included numerous cisterns into which sporadic rainfall was channeled over the paved surface of the city.

Cenote Noc Ac.

The effects of rapid, haphazard and environmentally-unsound inland development have been rapidly transferred to the waters of the eastern coast through extensive networks of submerged caves. A local cave diver told us that in some areas the divers have entered cenotes several miles inland and resurfaced in the ocean.

yucatan beach
Algae has grown on rocks at the water line.

The potential for widespread destruction of the fragile reef ecosystems has spurred some to call for responsible planning and innovative wastewater treatment, though lax environmental regulations and enforcement suggest that the call is not being heeded.

Despite some difficult adjustments to “Mexican time” and cuisine, the trip went off without a hitch.

Originally published in The Outcrop for 2006, UW-Madison Department of Geology and Geophysics, p. 16.