Past Programs
Earth Sciences - 2008
2008 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 | 1999 | 1998
Measuring sea level and the Earth
27/09/2008
The Earth isn't a sphere. It is flattened at the poles. These days, the Earth is measured from space. Sea level is measured by radar altimetry. The level of the sea changes by different amounts in different places. Some areas of Sumatra have seas which are rising at a rate of 30mm/year. Other areas in the Pacific are dropping by 20mm/year. A new mission, to be launched in October 2008 aims at measuring the Earth's gravity field from space in very fine detail. This will provide a reference point from which future changes can be measured.
Trinidad's Pitch Lake
12/07/2008
The Caribbean country of Trinidad and Tobago has a natural wonder of the world - a Pitch Lake. It's a basin of emulsified asphalt. Pauline Newman reports on efforts to study the area and the hope of discovering new forms of life.
The Eden Project
12/07/2008
An old clay quarry has been turned into a tourist attraction which focuses on how people interact with plants. The site consists of domes which act as greenhouses. The Eden Project has a partnership with Brisbane City Council. Paul Willis reports.
Midges as environmental indicators
31/05/2008
Midges comprise many kinds of very small two-winged flies. They are abundant in freshwater lakes and being very sensitive to temperature, are good environmental indicators. Cores from lakes show diversity and abundance of midges. They can reveal the temperature record going back 15,000 years. An assemblage of midges shows what the temperature was at any time. 2mm core intervals show changes every 10 years. Temperature can change quite quickly. 11,000 years ago, the Gulf Stream switched off and temperatures in Europe plunged 5 degrees. This happened over just 10 years. Things got cold very quickly. It was end of the ice age. Temperatures were increasing, and ice was melting. The result was large quantities of freshwater in the north Atlantic Ocean. The ocean current which drives the Gulf Stream was diluted. This switched the Gulf Stream off and plunged Europe into an Ice Age for 1,000 years. Today the Gulf Stream is thought to be 30% weaker. When the Gulf Stream returned, temperatures shot up quickly again.
Unicellular organisms in Antarctica - response to extended darkness and temperature change
03/05/2008
Andrew McMinn describes the challenges of 24 hours of darkness, and 24 hours of daylight, and the amazing transmission that takes place over about 6 weeks.
Andrew McMinn studies phytoplankton and zooplankton and observes how they cope with the extended darkness.
He suggests these organisms can survive in the darkness in low temperatures. It won't be so easy in the dark at higher temperatures.
Meltdown - tropical glaciers
26/01/2008
Glaciologist Lonnie Thompson pioneered the science of tropical ice core analysis. Ice cores, he says, are like tree rings, giving a long and accurate record, and clearly show the evidence of global warming. Thompson has been studying tropical glaciers for 30 years and Dan Grossman accompanied him on his 27th trip to Peru, and the Quelccaya ice cap.
