Converting algae to biofuel could be a sustainable solution to the need for liquid fuel in the United States, according to U-M researchers. Scientists in the chemical engineering department are working to create an effective method for converting the plant, which can be harvested continuously and grown in any water condition.
Savage's ocean-going organism of choice is the green marine micro-alga of the genus Nannochloropsis. To make their one-minute biocrude, Savage and Julia Faeth, a doctoral student in Savage's lab, filled a steel pipe connector with 1.5 milliliters of wet algae, capped it and plunged it into 1,100-degree Fahrenheit sand. The small volume ensured that the algae was heated through, but with only a minute to warm up, the algae's temperature should have just grazed the 550-degree mark before the team pulled the reactor back out. Previously, Savage and his team heated the algae for times ranging from 10 to 90 minutes. They saw their best results, with about half of the algae converted to biocrude, after treating it for 10 to 40 minutes at 570 degrees.
Since the 70s, the Magnetic North Pole has moved more than 1500 km at a rate of 10 kilometres a year. In the 1980s, this increased to 30 km a year. Today, the Pole travels 50, even 60 km - close to 150 metres a day.
Scientists don't quite know why its speed has increased these past 20 years. The magnetic pole is moving northwest of the geographic pole and may soon be across the Arctic Ocean in Siberia.
To find their bearings, sailors the world over must know the exact angle of difference between the two geographic and the magnetic north poles: the 'magnetic declination.'
The magnetic pole moves from the North to the South and vice versa every 250,000 years on average and does it very suddenly. Over 180 reversals have been recorded already.
As the intensity of the magnetic field tends to diminish, our planet becomes more susceptible to solar storms. In 100 years, the intensity has decreased by 15%."
Analysis of Earth's geologic record can reveal how the climate has changed over time. Scientists in New Zealand are examining samples from the rocky landscape once dominated by glaciers. They are employing a new technique called surface exposure dating, which uses chemical analysis to determine how long minerals within rocks have been exposed to the air since the glaciers around them melted. Comparisons of this data with other climate records have revealed a link between glacial retreat and rising levels of carbon dioxide in the air, findings that are informing scientists' understanding of global climate change today.
Science Bulletins is a production of the National Center for Science Literacy, Education, and Technology (NCSLET), part of the Department of Education at the American Museum of Natural History. Find out more about Science Bulletins at www.amnh.org/sciencebulletins .
The sea ice in the Arctic Ocean dropped below the previous all-time record set in 2007. This year also marks the first time that there has been less than 4 million square kilometers (1.54 million square miles) of sea ice since satellite observations began in 1979. This animation shows the 2012 time-series of ice extent using sea ice concentration data from the DMSP SSMI/S satellite sensor. The black area represents the daily average (median) sea ice extent over the 1979-2000 time period. Layered over top of that are the daily satellite measurements from January 1 -- September 14, 2012. A rapid melt begins in July, whereby the 2012 ice extents fall far below the historical average. The National Snow and Ice Data Center (www.nsidc.org) will confirm the final minimum ice extent data and area once the melt stabilizes, usually in mid-September.
In 1957 the Russians established a remote base in Antarctica -- the Vostok station. It soon became a byword for hardship -- dependent on an epic annual 1000km tractor journey from the coast for its supplies. The coldest temperature ever found on Earth (-89°C) was recorded here on the 21st July 1983. It's an unlikely setting for a lake of liquid water. But in the 1970's a British team used airborne radar to see beneath the ice, mapping the mountainous land buried by the Antarctic ice sheet. Flying near the Vostok base their radar trace suddenly went flat. They guessed that the flat trace could only be from water. It was the first evidence that the ice could be hiding a great secret.
But 20 years passed before their suspicions were confirmed, when satellites finally revealed that there was an enormous lake under the Vostok base. It is one of the largest lakes in the world -- at 10,000 square km it's about the extent of Lake Ontario, but about twice as deep (500m in places). The theory was that it could only exist because the ice acts like a giant insulating blanket, trapping enough of the earth's heat to melt the very bottom of the ice sheet.