T16. The remarkable sulfur properties

Sulfur is widely distributed on Earth, participating in a variety of geo- and biochemical processes. Elemental sulfur (S0) occurs in evaporite formations and in volcanic settings. In the past, climate disruption followed massive SO₂ injection into the atmosphere, trough eruptive plumes. Due to its complex polymerization behavior, pure S0 viscosity is highly temperature dependent, experiencing a 10,000 fold -increase at ~160_C, until a maximum around 186-188oC. This viscosity pattern is not respected in the presence of organics, H₂S(x), ammonia, halogens. This behavior remains poorly investigated, despite the high impurity of volcanic sulfur. S-layers accumulated at depth within volcanoes could explain contrasting geochemical signals at the surface following the scrubbing of critical species. In the ultimate case, S-viscosity variations could seal the volcanic system, leading to its overpressurization, and unheralded failure. Several eruptions were attributed to a system sealing at depth. Our knowledge of these processes is poor. Implications for hazard assessment are envisaged.
This session invites all studies that can improve the knowledge on S-properties in any state. Quantitative results, in situ sampling, mapping, continuous direct monitoring, remote sensing analyses. Experimental findings on S-viscosity at different pressure (mostly low) and temperatures (typical for hydrothermal systems) are particularly welcome