On the Map: Galapagos Islands - The Source - Washington University in St. Louis

A lava tube once filled with red-hot magma flowing down a volcano dwarfs the cavers exploring it. The keyhole profile of this lava tube, on the volcanic island of Santa Cruz, suggests the floor of an upper tube may have collapsed into a lower tube from an earlier eruption. The “rope” hanging down into the tube is actually a tree root. The islands have no fresh water, and the plants in the jungle canopy seek water everywhere — or just enough humidity to make it through the dry season. (Courtesy photo)

Mapping lava tubes

Aaron Addison, MSGISc, director of geographical information systems (GIS) and data services for Olin Library

Bob Osburn, MS, laboratory administrator for the Department of Earth and Planetary Sciences in Arts & Sciences

In addition to its extraordinary wildlife, the Galapagos Islands have another fascinating characteristic: lava tubes, a geographical feature caused by a very hot, voluminous and long-lasting eruption. Despite the islands’ fame, many of their lava tubes have never been explored. Addison and Osburn, who are also speleologists, have made three trips to map the tubes since 2009, most recently a 12-day trip in March 2013. Descending deep into the tubes, which are more than 300,000 years old, on the island of Santa Cruz, their group of cavers surveyed 19 caves for a total of 10 km. In March 2014, Addison will co-chair the 16th International Volcanospeleology Conference, which will be held on Santa Cruz.

Tracing a weedy evolution

Katherine E. Waselkov, PhD ’13 (Biology, Arts & Sciences)

THE BASICS

Location: 2,690 miles due south of St. Louis; 500 miles west of Ecuador
Governmental administration: Ecuador
Principal language: Spanish
Population: 25,000 (though none is indigenous)
Geography: a volcanic archipelago of 18 main islands scattered along the equator
Famous for: vast number of endemic species; Charles Darwin’s research on evolution
Little-known history: served as a major outpost for early 19th-century whalers and, before that, as a hideout for pirates raiding Spanish galleons

With funding from the National Geographic Society, in April 2011 Waselkov conducted field research in the Galapagos on its four native and endemic Amaranthus species. She skipped across seven islands to survey the native and endemic Amaranthuspopulations, gathering data to place them in a worldwide phylogeny of the genus and determine the phylogeographic origin of the species. She found that their greatest threat is human development. While native/endemic populations on uninhabited islands are thriving, one variety, A. furcatus (listed as “vulnerable” on the International Union for Conservation of Nature’s Red List of Threatened Species for Ecuador), is likely extinct. When she visited its historical collection site, she found it entirely developed.

Teaching giant tortoises

Susan Flowers, MA ’98, assistant director, Institute for School Partnership

Stephen Blake, PhD, visiting scientist, Department of Biology in Arts & Sciences

The Galapagos tortoise, for which the archipelago is named, provides an excellent case study for learning about animal migration. Why do some tortoises migrate up and down the islands’ volcanic slopes, and some barely move at all? Why is it that only adults migrate? In early May, Flowers and Blake traveled to Galapagos to meet with collaborators from the State University of New York, the Max Planck Institute of Ornithology, the Galapagos National Park Service and the Charles Darwin Foundation in order to launch the next three-year phase of an ongoing program that integrates ecological research with outreach and education. Next, the team will work with educators on Galapagos and colleagues at the St. Louis and Houston zoos to develop middle- and high-school-level instructional materials based on their tortoise research. The educational materials will be pilot tested with teachers in St. Louis and on Galapagos, and then broadly disseminated.

Listen to an interview with Stephen Blake at the National Geographic Society’s Newswatch website.

Addison’s field notebook. To the upper left are station numbers. From station 13 to 14, the distance was 15.87 meters, the heading was 210.5 degrees and the elevation was -2.5 degrees. These measurements were used to make the plan view of the tube. The small ovals to the side of the plan view are cross sections of the tube. The keyhole cross section and ladder to the upper right was formed when the upper tube collapsed into a lower one. The dotted circle beneath an ellipsoidal cross section downstream of that point indicates that here the two tubes run in parallel. (Courtesy photo)

First grade students from the Tomas de Berlanga school meeting a giant Galapagos tortoise. The students were participating in a field trip organized by the Galapagos Tortoise Movement Ecology Programme with the goal of introducing them to giant tortoises and their habitat, and to help them understand the research we are conducting and why we are doing it. (Christian Zeigler)

Christopher Casey and students from the Tomas de Berlanga school on Santa Cruz, Galapagos, interview Randal Keynes about his views on conservation and Science on Galapagos. Keynes is the great-great-grandson of Charles Darwin and is a passionate supporter of the Galapagos Islands. The tortoise in the frame may be 150 or more years old and could conceivably have been alive when Darwin was writing his world changing book On the Origin of Species by Means of Natural Selection. (Stephen Blake)

Stephen Blake, PhD, a National Geographic Society Explorer affiliated with Washington University in St. Louis, joined with the Academy of Science St. Louis to lead a BioBlitz gathering for Junior Academy of Science Teens at Tower Grove Park in St. Louis. Here Blake discusses techniques for tracking wildlife. (Sid Hastings/WUSTL Photos)

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