In this year's Geodynamics Seminar, we will explore the depth and breadth of scientific research related to Earth's present and past ice-sheets, glaciers and sea-ice, as well as extraterrestrial planetary ice. Invited speakers have been chosen from experts in the current frontiers in ice-related research, including planetary ice, climate records from polar and tropical ice cores, the Snowball Earth, subglacial volcanoes, ice rheology, ice sheet modeling, ice microkinetics, glacial erosion and tectonics, subglacial life and polar remote sensing. A field trip to Iceland in Summer 2006 will allow us to view some of the island's ice caps and glacial geology, the exposed mid Atlantic Ridge and evidence of ice-volcano interactions.

Denis Healey was the British secretary of state for defense from 1964 to 1970 and chancellor of the exchequer from 1974 to 1979. In this video segment, Healey reflects on the period in which he was defense secretary under Prime Minister Harold Wilson. He recalls the opposing interests of Germany and the United States with regard to nuclear strategy, explains his 'Healey theorem' of deterrence, and clarifies France's position that alliances can't coexist with nuclear weapons. Healey also assesses U.S. defense secretary Robert McNamara's quest for tidy solutions to 'insoluble' nuclear problems. In his interview conducted for War and Peace in the Nuclear Age: 'The Education of Robert McNamara,' Healey begins with a comparison between Soviet and North Atlantic Treaty Organization (NATO) conventional military strength. He elaborates on France's opposition to the notion of 'extended deterrence' and on his own role in persuading NATO to adopt 'flexible response' strategy. He traces the evolution of his military analysis of massive retaliation, describes his collaboration with McNamara in developing flexible-response doctrine, reiterates the expectation that SALT III would follow shortly after a ratified SALT II Treaty, and shares how he ultimately lost faith in flexible response. He also discusses the extraordinary growth of U.S. tactical nuclear weapons in Europe, Britain's response to the proposal for a Multilateral Force in the early 1960s, German chancellor Helmut Schmidt's distrust of U.S. president Jimmy Carter, and his own opposition to U.S. Euro-strategic missiles. As a fellow defense intellectual, Healey was encouraged by national security adviser Henry Kissinger's appointment: he was sure that detente could move forward. He admired Kissinger's boldness in dodging 'all official channels which he doesn't like anybody else doing,' but he was disappointed by Kissinger's failure to consult with allies. For the future, Healey believes that there should be fifty-percent reductions in strategic and conventional weapons, particularly when 'one side or the other has superiority.' He also advocates a 'nuclear-free corridor' to avoid accidental war.

This animation shows glacier recession at the Breidamerkurjokull glacier in Iceland. The data from 1973 is taken from Landsat 1 and the 2000 data is from Landsat 7. The Breidamerkurjokull glacier in Iceland has been measured by Landsat to be receding since 1973. The glacierologists in Iceland and here at NASAs Goddard Space Flight Center have measured the recession throughout the entire glacier and found different rates of recession in different areas. In general, the glacier seems to be receding at about 2% annually. It is extremely controversial whether this recession is caused by global warming.

This animation is a close up zoom into largest area of glacier recession at the Breidamerkurjokull glacier in Iceland. The data from 1997 is taken from Landsat 5 and the 2000 data is from Landsat 7. The Breidamerkurjokull glacier in Iceland has been measured by Landsat to be receding since 1973. In 1997, Landsat 5 took several other images of the glacier. It was thought by some glacierologists that this particular glacier was receding quicker in the late 1990s than it did in the late 1980s or 1970s. After careful analysis Goddard's Glacierologist, Dorothy Hall, concluded that the recession from 1997 to 2000 occurs at a similar rate to the recession between 1973 and 2000. It is extremely controversial whether or not this recession is caused by global warming.

This animation shows glacier recession at the Breidamerkurjokull glacier in Iceland. The data from 1973 is taken from Landsat 1 and the 2000 data is from Landsat 7. The Breidamerkurjokull glacier in Iceland has been measured by Landsat to be receding since 1973. The glacierologists in Iceland and here at NASAs Goddard Space Flight Center have measured the recession throughout the entire glacier and found different rates of recession in different areas. In general, the glacier seems to be receding at about 2% annually. It is extremely controversial whether or not this recession is caused by global warming.