Call for communications :
The aim of this symposium is to put into perspective the various contributions of volcano-speleology to geosciences, particularly in the following fields:
New occurrences: recently explored cavities, specific exploration techniques, …
Terrestrial and planetary geomorphology: the geomorphological expressions linked to the presence of lava tunnels (collapses, skylight, natural bridges, pseudo-dolines, pseudo-karst,…) are all elements of superficial observation which provide information on the nature of the terrain.
Hydrogeology: the supply of water to populations is one of the major challenges of the 21st century. The fact that huge basalt complexes can contain lava tunnels within them is a major advance in the research and exploitation of groundwater. In fact, the tunnels play the role of drains (infinite permeability) and therefore constitute privileged sampling areas for DWS drilling (drinking water supply). This is all the more sensitive in arid zones in volcanic environment (aquifer of Djibouti, Saudi Arabia, India, Africa, in particular).
Volcanology / origin of the cavities: the study of lava tubes and tunnels made it possible to better understand the dynamics and the methods of setting up fluid basaltic flows (poor in silica). This constitutes an element for the management of the volcanic risk.
Geoecology: the study of biotopes located in lava tunnels is a discipline in its own right, a branch of biology and exobiology.
National security and regional planning: lava tunnels can be significantly large (with volumes of several tens or even hundreds of thousands of cubic meters) and thus represent potential shelters in times of conflict. Certain Hawaiian, Micronesian or Marshall Islands tunnels were used for this purpose during the Pacific War.
Civil engineering: understanding the risk of existence of lava tunnels has been very useful, particularly in Hawaii or Reunion. Indeed, bulldozers fell under their own weight in lava tunnels in Hawaii during civil works.
Planetary archives: the lava tunnels were used as shelters, water points, places of worship, cockpit, necropolis, and thus host an important archaeological and prehistoric heritage.
Mineralogy: the study of secondary deposits makes it possible to observe formations composed of specific minerals. In situ mineralogical studies allow the discovery of new occurrences of exotic minerals in lava tunnels. Similarly, the micro-forms characteristic of lava flows (stalactite, flowstone, etc.) constitute a specific domain of lava tunnels.
Geotourism: from a sustainable development perspective (ecologically, culturally and environmentally tourism).