Science

Ninetyeast: An Ocean Adventure– Part I

I am as busy as ever these days with my coursework and research, but I though I’d make a little time for skepchick today. I’m working 10-14 hour days now running my samples on the mass spectrometer. This is how the life of a research geologist works– sometimes you’re off exploring the world, other times you’re working ridiculous hours in the lab trying to collect data. In-between runs on the mass spec, however, I plan to write more about my expedition to the Ninetyeast Ridge in Summer 2007. I’ll present a few short pieces on the expedition and the samples we collected. Then, I’ll write up a short piece on the data I’m currently collecting and on what preliminary results we have on our samples. The first of my pieces on the expedition is below. Enjoy! And stay tuned for Part II.

The sun was rising as the ship slowly steamed past the volcano Krakatoa, the first land we had seen in nearly two months. Although the time was just past six in the morning, almost everyone was out on deck. Those who were still sleeping were quickly roused and soon nearly all the ship’s scientists, many still wearing pajamas, were leaning over the port-side railing, squinting into the distance through the morning mist. Barely visible at first, the green shape of the island strengthened as the sun rose higher in the sky, the light erupting in an explosion of pink and orange and purple before softening to a pale yellow.

The sight of any land would have been mesmerizing after so many days at sea, but seeing a volcano come into view was nothing less than awe-inspiring.The island had a characteristic cone shape, but otherwise I would have had no idea I was looking at a volcano. I saw no lava, no billows of smoke. The island was covered in a lush, tropical forest and a few fishing boats were casting their nets into the turquoise waters surrounding the island. The scene was very peaceful, yet I knew that Krakatoa is one of the world’s most dangerous volcanoes.

Krakatoa does not erupt very often –perhaps once every few hundred years– but when the volcano does erupt it does so in a very violent fashion. During the last major eruption in 1883, Krakatoa shot ash tens of kilometers into the sky, covered large areas in lava flows, and created several large tsunamis. The once-large island literally exploded, leaving only a slender crescent moon of land. For weeks after the eruption, large, air-filled, floating rocks called pumice covered the ocean around the volcano. The scene must have seemed terrifying to the locals. Can you imagine a sea of floating rocks where an island once stood?

Now, over ninety years later, the volcano is silently sleeping. The volcano is not dead, however. From the depths a new volcanic island, called Anak Krakatoa or “Child of Krakatoa,” emerged from the water in 1927. Since then, this small volcanic island has been rising at the rate of several cm per week—an incredibly fast speed, geologically speaking. Mid-ocean ridges, for instance, spread at rates of several cm per year. Billows of ash sometimes rise from this new island and before long –maybe in five years, maybe in five hundred– the volcano will again erupt catastrophically. In the history of the Earth, five and five hundred years are both very short time periods. The Earth has been around nearly five billion years. So even if Krakatoa does not erupt for another five hundred years, the volcano is still considered very active in geologic time.

For the past fifty days, an insignificant amount to the Earth but a significant amount of time to me, I had been working as one member of a team of scientists who ventured out on an ocean expedition to study a chain of underwater volcanoes located in the middle of the Indian Ocean. The chain of volcanoes is called the Ninetyeast Ridge because the linear chain is located at 90° East longitude. Stretching about 5000 km north to south, the Ninetyeast Ridge is one of the longest chains of volcanoes in the world yet very little is known about these volcanoes. If the ridge were on land, there would be hundreds of geologists crawling all over the volcanoes with hammers and compasses and fancy computer equipment. However, because the volcanoes are located in the middle of an ocean and deep underwater, only a handful of scientists have ever gone to study the ridge. Indeed, some of the regions in which we traveled were so remote that sometimes we went for a week or two without seeing any other ships, even on radar. For much of the journey, we checked the weather reports and realized that the report consisted primarily of our own observations, which we reported back to shore periodically.

The expedition I was a part of was the first expedition to go to the ridge in perhaps twenty years. For this expedition a team of about twenty-five scientists from all over the world—America, Russia, India, Portugal, England, and South Africa—traveled to Thailand to meet the research ship. We spent three days traveling from Thailand to the top of the ridge and then spent about thirty-five days traveling down the ridge, carefully mapping the ridge and taking samples of the volcanoes. After our science was complete, we spent a week traveling back towards Singapore, our final port. Along the way, we first saw the volcano Krakatoa and then traveled alongside of the island of Sumatra, occasionally fending off pirates.

The volcanoes of the Ninetyeast Ridge will never erupt again, but many millions of years ago they were very active and would often erupt lava and ash. Many of the volcanoes used to be islands like Krakatoa. Over time, after the volcanoes died, they cooled and sank beneath the ocean waves. Eventually, they sank very deep into the ocean so that today they can only be studied remotely. They are too deep even for divers, so scientists must go out on a fancy research ship with specialized equipment for mapping and taking samples.

The volcanoes of the Ninetyeast Ridge rest silently under the waters, yet understanding how and why this long ridge of volcanoes formed is important in order to understand how our planet works and how the world’s active volcanoes were formed. As the famous geologist James Hutton said about geology, “The present is the key to the past.” Looking at the smoking Krakatoa, I realized this was true—in order to understand the deep, ancient volcanoes of the Ninetyeast Ridge I had to have an understanding of and appreciation for modern volcanoes like Krakatoa. However, I’d like to expand Mr. Hutton’s idea a little: I think that in geology, the past is also the key to the present. Understanding how these ancient Ninetyeast Ridge volcanoes formed, developed, and died is important in understanding how modern volcanoes will develop and, eventually, lie dormant on land or sink deep beneath the waves of the ocean, resting peacefully on the ocean bottom until some geologists come by to stir up the sediments with their various instruments.

Evelyn

Evelyn is a geologist, writer, traveler, and skeptic residing in Cape Town, South Africa with frequent trips back to the US for work. She has two adorable cats; enjoys hiking, rock climbing, and kayaking; and has a very large rock collection. You can follow her on twitter @GeoEvelyn. She also writes a geology blog called Georneys.

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9 Comments

  1. Fascinating stuff. I seem to recall reading somewhere that the 1883 eruption threw so much ash and dust into the air that it changed the color of the sunrise in Europe. I wonder if it looked anything like ours (caused by oil refineries).

  2. Hi!

    I’m hoping someone can help me out.

    I’m right at that point where I’ve met all my GenEd requirements and now must make a decision as to which direction I want to go in college. I’ve been looking at a career in Geology, but finding any reliable data on salary, job prospects, or even details of what I could expect to see in a job is rather scant.
    Evelyn, as you’re a research geologist, could you please elaborate on what you do on a normal day? Any idea what the job prospects are out of college?

    -Thanks!

  3. As a chemist I use a mass spec (usually electrospray) all the time to determine the molecular formula of my (organic) compounds. I am curious though, what kind of a mass spec a geologist uses, and what sort of information you get from it?

    I enjoyed your post and wanted to tell you hang in there – it does get better! :)

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