The Oldest Ice On Earth
This is a collaborative artist book with Todd Anderson about a team of scientists drilling for the oldest ice ever found by humans at a deep field research camp in the Allan Hills of Antarctica.
The book is in an edition of 12. It includes essays by William L. Fox (curator for Art + Environment at The Nevada Museum of Art) and John Higgins (the lead scientist from Princeton). Closed the Clamshell Box measures 21”x 15.75” Open the Book Measures 19.5”x30”. There are 16 photographic plates, 5 full bleed woodblock prints and 8 woodcut portraits of the eight scientists on the team. Three of the photographs are hand annotated by Ian van Coller. Blue Ice Drill Schematics with permission from The US Ice Drilling Program.
Layout by Ian van Coller. Photographs by Ian van Coller are pigment prints on Asuka. Reductive woodblock prints by Todd Anderson on Okawara. Drum Leaf bound in full cloth (with cloth-covered clamshell box) by John DeMerritt in Emeryville, CA.
The Transparency of Time
by William L. Fox
Water is the most common mineral in the universe. Mostly it occurs in its solid form, the rocks we call ice. On our planet, because of its singular “triple point” nature water can be solid, liquid, or vapor at one temperature and pressure (32.01ºF or 0.01ºC), although it most often appears as a liquid. It can also transition directly from solid to vapor, simply skipping over its liquid stage, during what we call sublimation. Water is, to put it technically, weird.
Water is known, of course, to flow in all its states, and as ice it moves fast or slow, and flows downhill or uphill, according to pressures put upon it. The Antarctic is the largest collection of ice on the planet. One small part of it, the Ross Ice Shelf, is formed by several glaciers flowing from the East Antarctic Ice Sheet and down through the Transantarctic Mountains. Those streams merge to form a mass that extends out over and floats upon the Ross Sea even as it is anchored to land. At an average thickness of 1,000 feet 188,000 square miles in extent, it is roughly the size of Texas—or France. It is the world’s largest ice cube.
The East Antarctic Ice Sheet is far larger—about the size of the entire United States and averaging 1.5 miles thick, or about 15,000 ft. It started growing about 45.5 million years ago and although Antarctica is the driest continent on Earth, it still accumulates more snow each year than it sheds by flowing in all directions to the ocean. The Transantarctic Mountains are the ice sheet’s only significant barrier, and there are places where the downsloping ice doesn’t make it through, but instead flows partway up the ramparts and then stops. The Allan Hills, an outlier of the mountain chain, is exactly such a place.
The Allan Hills Blue Ice Field, located about 135 miles by airplane from McMurdo, the largest base on the continent, is one of the most remote field camps on the planet. Where the ice is stopped by the hills, it is scoured by winds that ablate it—sublimating away the ice—and exposing the blue ice underneath. Drill down there and you will find the oldest ice so far cored by scientists. In 2020 they were able to bring up ice—and trapped bubbles of atmosphere—around two million years old. Those bubbles are primarily what they want to examine, as they help us to compile a deep climate record.
Unfortunately, estimates for the levels of greenhouse gases (CO2) during this period are imprecise and rely on indirect approaches with large uncertainties. Current best estimates range from 300–420 parts per million (ppm), levels that are both lower than and similar to the present day (417 ppm as of August 2022). Ice cores from the Allan Hills BIA provide the first opportunity to reconstruct ancient greenhouse gas levels (CO2, CH4, and others) directly using 3-million-year-old samples of Earth’s ancient atmosphere.
In addition, as the oldest recovered and dated ice in Antarctica, the ice cores will offer invaluable information on the climate and ice sheet history of this polar continent during warmer times. These records will be vital to scientists trying to understand Earth’s climate system in the past, providing important benchmarks for the calibration of numerical models of Earth’s climate system and ultimately improving our predictions of how Earth’s climate will change in the near future.
Chronostratigraphy is one word for it, reading the successive layers of rock through time. Only by examining past records of climate are we able to understand what we’re facing in the future, so this is non-trivial, perhaps even existential science.
The other reason to have people wandering around the blue ice fields is that the ablation of the surface brings up things found deep in the ice. Among the objects you find, while
Ancient Bubbles Tell Future Climate Stories
by John A. Higgins
There is both profound and practical interest in understanding the history of our planet, and modeling how natural factors and human activities have changed and will continue to change Earth’s climate. Our knowledge of Earth’s climate history is grounded in the geologic record through measurements of chemical, biological, and physical properties of earth materials—for example, the widths of tree rings, or the chemical composition of fossil shells preserved in marine sediments, or bubbles of ancient air trapped in polar ice.
Ice cores, borings through the polar ice sheets, play a central role in our understanding of Earth’s climate history, for two reasons: First, the ice record provides very detailed information about past temperatures, snow accumulation, atmospheric circulation, atmospheric dust and aerosols, and many other properties directly connected to climate. Second, the ice traps small samples of the atmosphere, preserving a highly accurate record of greenhouse and other atmospheric gases. This atmospheric record is a unique attribute of ice cores and provides the best evidence for a strong link between atmospheric carbon dioxide (CO2) and Earth’s climate.
The oldest ice cores are in East Antarctica, the largest and most stable of Earth’s polar ice sheets. Until recently, the continuous ice record extended back only 800,000 years before present (800ka B.P.), and while the existing data provided a robust foundation for our understanding of Earth’s climate, they did not extend back far enough to provide information from periods when the climate was warmer and/or greenhouse gas levels were higher than today. Such information would be crucial for understanding how climate will evolve as greenhouse levels rise through the twenty-first century.
The 800ka limit of Earth’s ice-core record was shattered in 2010–11 by scientists from a consortium of universities, including Princeton and the University of Maine, working in the Allan Hills Blue Ice Area (BIA), a part of East Antarctica long known to harbor ancient meteorites. The area is characterized by strong katabatic winds that scour and ablate the ice surface, resulting in ice loss that is balanced by slow glacial creep. At the Allan Hills, a series of rock formations that pierce the sea of the East Antarctic ice sheet marries strong surface winds with steep bedrock topography, which ultimately brings ancient ice (and meteorites) to the surface. The group, drilling a 3-inch, ~475 foot borehole, discovered ice that was dated to ~2.7 million years.
Using a novel geochemical technique developed by Professor Michael Bender, they were able to determine age by comparing the decay of a particular isotope of argon (40Ar) in a sample of air liberated from the ice to that of the same isotope in the modern atmosphere. This and subsequent drilling expeditions in 2015–16 and 2019–20 have focused on recovering large quantities of ancient ice to extend the direct record of Earth’s atmosphere back into periods when Earth’s climate was warmer than today. Although still a work in progress, our preliminary results from the 2019–20 expedition indicate that there is ice as old as 3-4 million years (!) at the Allan Hills BIA.
The discovery of well-preserved Antarctic ice that is 3–4 million years old is truly remarkable, as it makes possible, for the first time, direct reconstructions of greenhouse gases in Earth’s atmosphere during a period that is widely seen as a geologic analogue for human-induced global warming predicted for the coming decades. The Mid-Pliocene (3.3–3 million years ago) is the most recent period in geologic history during which Earth’s climate experienced sustained warmth; global temperatures were 2–3 °C higher than preindustrial eras and sea level was ~60 ft higher than present.