5 weeks 5 days
Written in Mud
Submitted by Exp 350 Paleo on Sun, 05/25/2014 - 21:23
A micropaleontologist writing:
I have spent the best of my life, a gentle 25-year stretch, studying fossils: micro-organisms called planktonic foraminifers from samples raised from the deep sea to try figure out the inner working of the oceans through time and what it means for past climates on Earth.
For me and for a few scientists like me -some at sea & some in labs- mud is the book in which geological events are written. Using a microscope, we can read this book. We estimate the ages and ocean temperatures. Easy! With a bit more kit in the lab, we can tell more precisely, what and when things like glaciations and deglaciations or other major changes have happened and what might have been the implications.
Cambridge, 27th of March.
Anxious: Still in the lab, all packed and ready for Exp 350.
Mud, from almost all oceans, I held you in my hands. I dream of you.
Mud, like a child, I played with you thousands of times, with my sieves and a water spray.
Mud, hundred, thousand, hundreds of thousands or millions of years out of the light.
Mud, once back in the light, brown or green, rich in tones, shining or matte. I’ll meet you there.
Mud, I wait for the microfossils hiding inside to be clean and dry, ready for my eyes.
Philippine Sea, 27th of May.
For one last time: Core on deck.... Core on deck! Game over, end of drilling!
That was my first time on JR. Now, I have some mud, my samples are packed, ready for home. That was my first time on JR. Now, I have more friends, my memory is full, I am ready to leave.
That was my first time on JR. Now, I can work, for months in the lab, I will read in the mud.
We have cored some good mud. This mud is lying under the Kuroshio Current. Amazing people working for IODP have drilled through a huge pile of it - the pile is called a sedimentary drift - and they have recovered hundreds of meters of mud for us into hundreds of 1.5 m long sections of cores. Such a large accumulation of sediments comes from a number of factors. Some of the scientists who have spent 2 months on JR are going to investigate them all together for months and years to come. Others among them will study the rocks found below the mud. Since these are made mostly of volcanic material they will help understand better some of the deep earth processes involved in a back-arc area such as that of the Izu-Bonin-Mariana subduction zone.
Wait a minute. Here, what causes the changes recorded in the “mud book”?
1) Volcanic particle inputs - many volcanoes around here and even more under the ocean waves
2) Dust influx - strong winds bring here more of less dust from the land nearby
3) Action of oceanic currents – Kuroshio at the surface & other deeper currents flowing from far away
4) Oceanic biological productivity - life everywhere, tiny ones feeding bigger ones
5) Tectonic - a mountain range is going up as one plate goes down, the other one near the IZU arc
6) Combinations of some of these - things are tricky for sure!
7) Other causes yet unknown – likely, because I know almost nothing
With the scientists of Exp. 350, I plan to use some of the mud recovered by IODP to understand better what a big current like the Kuroshio does to the Earth climate. What it interacted with and what were the consequences over the last few millions of years. For this, I will give all my attention to some of the many parameters at play in an area very close to the largest ocean on Earth: The Pacific Ocean.
The study of the planktonic foraminifers that are still hiding in my mud sample selected along an almost 1km-long record will help me in my quest.
I will never come back here, but I hope that on a sunny day my dreams of mud will come true again.