RICHARDSON, Texas (July 16, 2003) - If you're the type who shudders when the mercury dips below freezing, chances are you wouldn't care for "Snowball Earth."

Although it's a matter of conjecture and the subject of much debate, some scientists believe that the Earth underwent profoundly cold periods from 750 million to 600 million years ago - so cold that all water, including the surface of the oceans, was frozen solid. The entire planet, according to this hypothesis, was a literal snowball.

Scientists from The University of Texas at Dallas (UTD) and Hebrew University of Jerusalem plan to test the controversial theory by studying 700-million-year-old rocks in northern Ethiopia.

UTD Geosciences Department head Dr. Robert Stern, his research scientist colleague Dr. Nathan Miller and Professor Dov Avigdad of Hebrew University received a three-year, $150,000 grant to conduct their study from the Binational Science Foundation, an organization established by the governments of the United States and Israel to promote joint scientific and technological research between the two countries. Next October, the scientists, along with researchers from Mekele University in Ethiopia, hope to begin their field examination of Ethiopian rocks from the Neoproterozoic era.

"This project will test the Snowball Earth hypothesis, which explains perplexing features of 800 million- to 570-million-year-old sedimentary deposits that indicate the Earth's climate fluctuated dramatically between episodes when the planet was covered with ice and episodes when the climate was much hotter than it is today," said Stern. "The evidence includes thick glacial deposits on all continents sandwiched between warm water limestones and chemical indications that primitive photosynthetic marine life died off during so-called 'Snowball' episodes."

UTD researchers, along with Italian and German scientists, earlier this year reported that the northern Ethiopian rock formations appear to be the first documented evidence of Snowball Earth events in the Arabian-Nubian Shield, a huge, poorly known region that stretches north to south from Israel to Ethiopia and east to west on either side of the Red Sea. UTD geoscientists have studied there since 1982.

The goal of the project in Ethiopia, according to Stern, will be to establish the sequence of events recorded in the rocks and interpret the results to better understand how and why Earth's climate was changing at that time.

Meteorological and geological events which may have occurred in the Snowball Earth scenario should not be confused with ice ages that took place a few million years ago - a brief span of time on the geologic clock.

"The events we are talking about are much, much older," Stern said.

About UTD
The University of Texas at Dallas, located at the convergence of Richardson, Plano and Dallas in the heart of the complex of major multinational technology corporations known as the Telecom Corridor, enrolls more than 13,000 students. The school's freshman class traditionally stands at the forefront of Texas state universities in terms of average SAT scores. The university offers a broad assortment of bachelor's, master's and doctoral degree programs. For additional information about UTD, please visit the university's Web site at http://www.utdallas.edu.