The Laguna del Maule volcanic complex in Chile is a large, complicated and explosive landscape that, oddly, lacks the classic cone seen on many volcanoes, including Fuego, the Guatemalan volcano that killed hundreds in a June 3 eruption.
It’s a major task to understand a mountaintop region that has erupted 50 times over the past 20,000 years. But the starting point for grasping the big picture of a study published today (June 27) in Science Advances is pretty simple: It’s the ring that standing water leaves on a bathtub.
Like the shore of an ancient lake, a bathtub ring must be horizontal when it forms. But, as University of Wisconsin–Madison professor of geoscience Brad Singer noticed years ago, the ancient, elevated shoreline at Maule now slopes from a low spot in the north to a high spot in the south.
The Maule volcanoes, located in a region that has seen enormous eruptions during the last million years, are restless. Since 2007, satellite instruments have measured an average uplift of 8 inches per year – far and away the fastest and longest measured rise of a restless volcano in the world, and an unmistakable sign that molten rock under the area is rising.
Singer, a volcanologist and specialist in dating rocks, currently directs a five-year National Science Foundation project to explore Maule with a wide variety of geologic techniques. Understanding why that rise is taking place, and what it portends, are two central goals of the project, which brought dozens of scientists and students to the site.