Mail archives:
Polar Mail
December 17, 2007
Question
Hey lava walkers, I'm so excited to read about Mark Kurz! I was out with him on the R/V Roger Revelle Dive and Discover expedition to the Galapagos Islands when he was investigating the chemistry of the gases trapped in the basalt lava rocks on the seafloor. Dr. Kurz, what are some of the geochemical differences between the Galapagos volcanic rocks and Mt. Morning?
Best,
Christy Reed
Seattle, WA
Answer
Dear Christy,
Nice to hear from you Christy - that was a great trip to the Galapagos. The basalts here are very different in chemical composition from those in the Galapagos; they have more sodium and potassium and are called alkali basalts. The Galapagos volcanoes occur in the middle of the ocean basins, whereas the volcanoes in this area are erupted in adjacent to continental rocks, so they are totally different geologic settings. Our scientific goals are completely different also. Here we are studying the evolution of the cold desert Antarctic landscape using cosmogenic nuclides and LIDAR, whereas in the Galapagos we were studying the seafloor. I'm glad you are following the website and will be happy to give you more details.
Best regards,
Question
Dear Andrea Burke,
I am writing to you from the Republic of Ireland and I wish to ask a question about your research of lava flows and the weathering of rocks on Mount Morning.
I am interested in Geology and in rocks, especially the rocks on the Planet Mars. I, like thousands more people, have been following the Mars Exploration Rovers Mission which landed on Mars in the Gusev Crater Area of Mars. I am also interested in how the rocks on Mars have been shaped over millions of years, and think your research into how long the weathering of rocks at Mount Morning takes may help the scientist that study Mars.
In the incredibly dry atmosphere of Antarctica there's virtually no water to cause erosion. And in some areas like Mt Morning there's very little snowfall, either. But ice underneath the rocks still expands and contracts as the temperature fluctuates from around freezing (32 degrees F) to -50 degrees F or colder. During the region's nearly six-month summer of continual daylight, the Sun can even heat the rocks enough to melt patches of snow.This slow freezing and thawing eventually breaks apart the rock and sometimes pushes the pieces into odd, geometrical arrangements. It takes a long time. I will be following Expedition 3 and hope you will have a great time with your research. I would love to have the opportunity to visit Antarctica on a vacation trip sometime.
Best wishes
Bill Reddin
Republic of Ireland
Answer
Dear Bill,
Thank you for your interest. Indeed, the Antarctic landscape is often used as an analog for the Martian landscape. As difficult as it is to get to Antarctica, it is much easier to get to than Mars! One reason why we study Antarctica is because its cold and dry climate is unique on the Earth, and is most similar to the environment on Mars.
Take care,
Question
Does it get colder at night in Antarctica, or is it the same temperature if all other conditions are the same?
Geoff O'Donoghue,
Cambridge, MA, USA
Answer
Dear Geoff,
Thank you for your question. The sun never sets here during the summer, but as it circles around the sky, it is higher at midday and lower at midnight. This small variation in the height of the sun does have an effect on the temperature throughout the day, but nowhere near as big as the effect observed at mid-latitudes or low-latitudes. The effect will also be strongly dependant on local topography (e.g. if the sun dips behind a nearby mountain).
Best,
