LC: As a biology student, I’ll sometimes be walking down the street, living my daily life, and something will stop me–“Why are this tree’s leaves this shape?” or whatever. I wonder, when do geology or seismology or the earth sciences pop up in your daily life?
ML: Well this is particularly because in the last five years I’ve started doing a bunch of scientific work in eastern North America, deploying seismometers to understand the structure of the crust and mantle. I really do experience driving around and seeing rocks on the side of the highway differently I think than probably most people. And I’m a geophysicist, I work with seismic data and think about the deep earth; I’m not a classical geologist who spends a lot of research time walking around on outcrops trying to look at rocks. But earth scientists really do get into the mind of looking at a rock or an outcrop or whatever and thinking about the story that it tells about how the Earth works.
I can see East Rock out my office window here. Do you know what East Rock is? It’s a good view. You can see right there the top of east rock. It’s a little blocked. So do you know what East Rock is?
I would guess it’s cooled lava…?
It is cooled lava, it is. Do you know from when?
East rock is amazing because it is telling the story of the breakup of Pangea 200 million years ago. Say 270 million years ago, this area was like what the Himalayan mountains are today—huge collision, massive mountain range. Later on in time, around 200 million years ago, that supercontinent broke apart—why? Good question! We don’t know. That’s not a solved question, why supercontinents break apart. So it broke apart and it’s analogous to what you have in East Africa now, where there’s a ton of volcanoes and the African plate is basically splitting apart very slowly over geologic time.
What happens is you rip a piece of fabric apart and on the edges you get these jagged little strands. All of the Connecticut river valley and the Hartford basin is one of these. It’s filled with sedimentary rocks you can see, they’re very beautiful, and then it’s filled with these volcanic features like east rock and west rock and sleeping giant and Hamden. And these tell the story of this super fundamental earth process that we don’t understand. So I will say that driving around on the highway or hiking or whatever, I am very attuned to what story the rocks are telling us.