Tuesday, November 27, 2007

Do you see what I see?

When I was in Tanzania, I found out a curious fact. When I am scanning the bush around me, I don't pick up leopards or other cats at all. I notice birds and ungulates, am often one of the first ones to see them, but a cat would have to be chewing on my leg before I can find it. Possibly this is because I spend most of my time in Alaska with half an eye on the look out for moose or bears and I am always looking for a new bird. My search image is well developed for these types of shapes and motions....but I've never spent any significant time in an area where it was important to notice large cats - or for that matter, snakes, which I've nearly stepped on at times.

Very similarly, the scientists looking at the core bring their areas of greatest experience with them when they look at the core. A volcanologist will tend to notice igneous features while, for a sedimentologist, the most obvious parts of the same section of core will be the layering and texture patterns of the grains of sediment. We all do this to a greater or lesser extent - we tend to be drawn to and pay more attention to the things that interest us most or that we are most familiar with.

One of the great strengths of the multi-disciplinary nature of ANDRILL is that everyone brings their special area of interest to the endeavor and then shares their ideas and observations with others who have very different starting points and backgrounds. The scientific discussion then involves exploring the ways in which the data might fit together to answer the big question of what was happening in this area of Antarctica in the past. The final explanation that is rendered must accomodate all data from many science disciplines, making it a much stronger statement than one coming from just one viewpoint.

The interpretation of the SMS sediment core needs scientists from both tectonic and environmental perspectives. For example, evidence in the core for deeper water environments may indicate an increase in sea level caused by ice sheet melting or it might indicate rifting and subsidence in the plates of the area - or more likely, a combination of both. We are looking in the core at a record of sedimentation and erosion. Sedimentation happens in where there is both space for sediment to accumulate and sediments in the area to fill it. We need a complete picture of both the tectonic and environmental factors that might be creating the sediment and space for it to fill in order to understand what was happening here in the past.

Take a look at the picture at the top and see what animal you notice first (there are two). What are the things you focus on in an outdoor environment, what do you see first? How about in indoor environments? How does what you notice differ from what someone else in your school or family notices?

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