Case Study: Discovering Life in the Extreme

Investigate Sea Floor Spreading

Imagine it is 1977 and you are a pioneering geological oceanographer. You are part of a team of ocean geologists leaving port on a large ship to research some of the thousands of unanswered questions about the deep ocean floor. Your team will investigate a sea floor spreading center near the Galapagos Islands in the Pacific Ocean. You expect to find hot springs, or a source of intense heat releasing from somewhere beneath the ocean crust. While on the research voyage, you will tow instruments from behind the research ship. These instruments will include temperature sensors and a camera system to record video footage of the spreading center where two of Earth's great tectonic plates are spreading apart beneath the eastern Pacific Ocean. In the opening created by the spreading plates, magma rises to create the Galapagos spreading center. You and your team of geologists are filled with excitement and promise of discovery.

Life in a Extreme Environment?

Scientists have long understood that the sun is a necessary ingredient for life, but at the time of this cruise in 1977, they are beginning to wonder whether or not life without the sun's energy might also be possible. In the final 13 minutes of recorded camera footage, your ship's instruments pick up a temperature anomaly, or a noticeable and dramatic change in water temperature. The underwater camera zooms in and captures a glimpse of an unexpected black and white image; shimmering water and what appears to be clam shells...and then the camera runs out of battery power leaving the scientists to wonder in awe at what they had seen. Was it the first signs of life ever to be recorded in extreme submarine environments?

A Biological Community

In fact, it was! The irony of this revolutionary finding at the sea floor was that there were no biologists on board to help explain how life might exist at these seemingly hostile ocean bottom hot spots. This brief but remarkable sighting initiated a series of questions within the scientific community and the rush to explore the possibility of life at the bottom of the ocean began. The later surprise discovery in 1979 that organisms could not only live without sunlight but were somehow thriving in its absence completely redefined the way scientists understood the requirements for life.

In this chapter, you will conduct your own exploration of hydrothermal vents at an ocean spreading center (the East Pacific Rise), using a data portal called GeoMapApp that allows you access to data collected over the past thirty years from these remarkable underwater volcanoes. You will have an opportunity to experience some of the wonder and excitement of seeing communities of lifeforms that very few humans have seen before, and you will be able to make observations about patterns in topography, biology, and chemistry that might explain how these communities exist in an extreme environment of high pressures, unstable tectonics, and hot acidic solutions.