The Zurich’s Long Night of Open Museums provides the opportunity to go see various (special) exhibitions in the city of Zurich for one night. Visitors could find focusTerra, the Earth science museum of ETH Zurich, in the list of participating museums. It is located in the luminiferous atrium of the Earth Science department building and explains the geologic processes which form and happen on our planet.
Beside the permanent exhibition which displays the internal structure of the Earth, meteorites and the development of the solar system, processes like earthquakes, plate tectonics, volcanic eruptions, mountain building, and rock deformation, visitors can understand the formation of crystals, the nature and origin of gems and minerals, and the development of sediment formations. One of the highlights of the museum is the earthquake simulator which is especially interesting for people who want to experience what an earthquake feels like. In addition to the permanent exhibition, visitors have currently the chance to see the ‘Earth’s treasures & resources exhibition’, a temporal special exhibition in the museum that focuses on the use and value of fossil and mineral resources. A second temporal exhibition of focusTerra deals with Supervolcanoes and their impact on life on Earth. Several talks feature the topic as well and are given throughout the year. The kick-off event was the Long Night of Open Museums 2016.
Therefore, Jana Schierjott and Simon Preuss decided to participate in the Zurich’s Long-Night of Museums offering a workshop on dike propagation in the Earth’s crust. This experiment is able to simulate what happens in the subsurface before a volcanic eruption. The idea was that everybody coming to the focusTerra this night could make their own volcano experiment and see how a dike propagates upwards in the Earth to lead to a possible eruption. The dike experiment was not only meant for children, also adults were very interested in understanding how and why dikes propagate through the Earth and wanted to run their own little dike experiment.
Simon explaining to some of the visitors how the mini-experiment works and why dikes look like sheets.
It consisted in injecting air or a coloured fluid with the help of a syringe into the bottom of a transparent plastic cup that was filled with gelatine. The less dense air or fluid then propagated upwards as a thin sheet (not as many visitors thought as a pipe-shaped dike). This happens because the dike always tries to diminish the amount of energy needed for its propagation and orientates itself accordingly to the stress orientation-situation in the gelatine. Finally, if enough fluid was injected it reached the surface and erupted suddenly which left most experimentalists with a surprised look on their face.
Additionally, Jana and Simon provided 4 big gelatine volcanoes on a wooden board which simulated the often observed flank eruptions or long-stretched fissure eruptions that are for example observed on Iceland or Hawaii. Many visitors were quite surprised and very interested in this phenomena since the typical, “perfect” volcano they know erupts from the main vent on the summit.
Jana preparing a volcano eruption using one of the big gelatin cones. In the end, a nice flank eruption was visible to the visitors.
All in all, it was a very successful evening for all the visitors of the focusTerra exhibition who came to learn something about Supervolcanoes and how they evolve.
Also, Simon and Jana were very happy with the outcome: more then 60 single dike experiments were conducted by the visitors plus the additional bigger cone-shape volcano experiments and many questions on the topic of volcanoes could be answered.
Preparation of the gelatine experiments a day in advance. Before the actual workshop could begin, Simon and Jana had to prepare all cups with gelatin, the gelatin cones and do some test-eruptions.
