The influence of magmatic system properties on volcano dimensions, morphology and evolution
| Giovedì 6 aprile 2017 | ore 11.30 | Angelo Castruccio – Universidad de Chile | Sala seminari – INGV Sezione di Pisa
In this study we developed a simple model for the extrusion of lava flows and volcano edifice construction and its topographic profile that allows us to estimate some of the magma system properties feeding the volcano, such as magma chamber depth and volume and conduit dimensions. Such properties can be reasonably constrained within the framework developed here under certain assumptions.
According to our model, the shortening of emitted lavas observed through the life of many volcanoes can be due to the growth of the volcano itself. We explored the dependency of the morphometric characteristics of the volcano edifice on magma plumbing system properties, where volcano and lava flow dimensions can be interpreted as indicators of key properties of the magmatic system underlying effusive volcanoes. Our results indicate that large volcanoes (>2,000 m height and base radius > 10 km) usually are basaltic systems with overpressure sources located more than 15 km depth. On the other hand, smaller volcanoes (<2,000 m height and basal radius < 10 km) are associated with more evolved systems where the chambers feeding eruptions are located at shallower levels in the crust (< 10 km).
We suggest that the model proposed in this work should be used in conjunction with geophysical and petrologic methods to better constrain the key properties and the nature of the complex magmatic systems of arc volcanoes.