Science News Reader Supplement HERE & NOW Volcanism Vicki M. Harder

Although scientists have been studying volcanoes for many years it hasn't been possible until recently to obtain information from volcanoes that occur along the oceanic spreading center. There is a close relationship between plate tectonics and the locations of the different types of volcanoes. The most extensive volcanic system of Earth lies beneath the sea, along the oceanic spreading center. Understanding volcanism in the context of plate tectonics is important not only for improving our scientific knowledge of these processes but also for our ability to assess the hazards associated with volcanoes and to predict eruptions. New technology developments allow scientists to observe and gather data that has never before been possible.

As reported in the articles in the Science News reader, volcanoes can occur in unusual, inaccessible settings. Recent volcanic eruptions have occurred under an Icelandic glacier, off the coast of the big island of Hawaii, and along the Gorda Ridge, a spreading center in the north Pacific Ocean. Each of the Science News articles indicate how scientists are using new technology to advance their knowledge of the plate tectonic processes.

In the Science News reader article Volcanoes under ice: Recipe for a flood the erupting volcano occurs under the largest glacier on Iceland, which is a part of the Atlantic mid-oceanic spreading center. Records of the eruption of this particular volcano have been kept since the 12th century since rapid melting of the overlying glacier and subsequent flooding occurs. Radar images show the melting of the glacier and follows the flooding to the Atlantic Ocean. Unfortunately, because the volcano is covered by the glacier, scientists are unable to directly witness the eruption or collect specimens from an active spreading center.

Another volcanic eruption along the spreading center is discussed in the Science News reader article Spying on a deep-sea eruption. This volcanic eruption took place along the Gorda Ridge in the Pacific Ocean, another occurrence of a spreading center volcanic eruption. Since this eruption took place at a depth of 3100 m scientists were able to witness sea-floor spreading via remote sensing techniques using a remote camera.

Loihi is the next addition to the Hawaiian island chain, as covered in the Science News reader article Hawaii's Next Island Suffers Setback. It is an underwater volcano growing off Hawaii's south coastline that is connected to the Hawaiian hot spot, a fixed point on the Earth's surface defined by long-lived volcanism. Loihi is giving scientists a first-time ever view of how the islands of the Pacific ocean formed. Scientists have used a submersible to view Loihi directly and have plans to place seismometers (to study earthquakes) and chemical sensors on the summit for the collection of additional data.