The Snowball Earth is a geohistorical hypothesis that proposes during one or more of Earth's icehouse climates, the planet's surface became nearly entirely frozen with no liquid oceanic or surface water exposed to the atmosphere. The most academically mentioned period of such a global ice age is believed to have occurred some time before 650 mya during the Cryogenian period, which included at least two large glacial periods, the Sturtian and Marinoan glaciations.
Richard Alexander Fullerton Penrose Jr., better known throughout his career as R. A. F. Penrose Jr., was an American mining geologist and entrepreneur.
The Cryogenian is a geologic period that lasted from 720 to 635 million years ago. It is the second of the three periods of the Neoproterozoic era, preceded by the Tonian and followed by the Ediacaran.
Reginald Aldworth Daly was a Canadian geologist. He is best known for being one of the first proponents of the giant-impact hypothesis of the formation of the Moon.
Robert Ferguson Legget was a civil engineer, historian and non-fiction writer. He is internationally known for his contributions to engineering, geology and building research and standardization. He is credited with the establishment of co-operation amongst Canadian geotechnical engineers, geologists and pedologists.
Arthur Philemon Coleman was a Canadian geologist and academic.
William Walden Rubey was an American geologist.
Daniel Paul Schrag is the Sturgis Hooper Professor of Geology, Professor of Environmental Science and Engineering at Harvard University and Director of the Harvard University Center for the Environment. He also co-directs the Science, Technology and Public Policy Program at the Belfer Center for Science and International Affairs at the Harvard University Harvard Kennedy School. He is also an external professor at the Santa Fe Institute.
Luna Bergere Leopold was a leading U.S. geomorphologist and hydrologist, and son of Aldo Leopold. He received a B.S. in civil engineering from the University of Wisconsin in 1936; an M.S. in physics-meteorology from the University of California, Los Angeles in 1944; and a Ph.D. in geology from Harvard University in 1950.
Andrew Herbert Knoll is the Fisher Research Professor of Natural History and a Research Professor of Earth and Planetary Sciences at Harvard University. Born in West Reading, Pennsylvania, in 1951, Andrew Knoll graduated from Lehigh University with a Bachelor of Arts in 1973 and received his Ph.D. from Harvard University in 1977 for a dissertation titled "Studies in Archean and Early Proterozoic Paleontology." Knoll taught at Oberlin College for five years before returning to Harvard as a professor in 1982. At Harvard, he serves in the departments of Organismic and Evolutionary Biology and Earth and Planetary Sciences.
Albert Francis Birch was an American geophysicist. He is considered one of the founders of solid Earth geophysics. He is also known for his part in the atomic bombing of Hiroshima and Nagasaki.
Michael Manga is a Canadian-American geoscientist who is currently a professor at the University of California, Berkeley.
The Marinoan glaciation, sometimes also known as the Varanger glaciation, was a period of worldwide glaciation. Its beginning is poorly constrained, but occurred no earlier than 654.5 Ma. It ended approximately 632.3 ± 5.9 Ma during the Cryogenian period. This glaciation possibly covered the entire planet, in an event called the Snowball Earth. The end of the glaciation was caused by volcanic release of carbon dioxide and dissolution of gas hydrates and may have been hastened by the release of methane from equatorial permafrost.
Heinrich Dieter 'Dick' Holland was an emeritus professor in the Earth and Planetary Sciences department of Harvard University. He made major contributions to the understanding of the Earth's geochemistry, especially large-scale geochemical and biogeochemical cycles. He has also contributed to the field of planetary chemistry and planetary evolution.
The Sturtian glaciation was a worldwide glaciation during the Cryogenian Period when the Earth experienced repeated large-scale glaciations. As of January 2023, the Sturtian glaciation is thought to have lasted from c. 717 Ma to c. 660 Ma, a time span of approximately 57 million years. It is hypothesised to have been a Snowball Earth event, or contrastingly multiple regional glaciations, and is the longest and most severe known glacial event preserved in the geologic record after the much earlier Huronian glaciation.
Stanley Awramik is an American biogeologist and paleontologist. He is best known for his work related to the Precambrian. In 2013, he was inducted as a fellow of the Geological Society of America.
Laurence L. Sloss was an American geologist. He taught geology at Northwestern University from 1947 until his retirement in 1981.
An Yin was a Chinese-American earth scientist and a Distinguished Professor of Geology at the University of California, Los Angeles (UCLA). His early work explores the mechanical origin and kinematic evolution of low-angle normal faults and thrust systems in the North American Cordillera. He is perhaps best known for his work on the tectonic evolution of the Himalayas and Tibetan plateau. His research interests shifted in later years to slow-earthquake mechanics, early Earth tectonics, and planetary studies.
Abhijit Basu is an Indian geologist. His research has focused on studying properties of rocky planetary bodies. He has been active in science education and is Class of 1948 Herman B Wells Endowed Professor at Indiana University Bloomington.
