COMET Webinar: Dr Philip Benson (University of Portsmouth). 9th March 2022

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From: Scott Watson <C.S.Watson@xxxxxxxxxxx>


Dear Colleagues,

COMET (The Centre for Observation and Modelling of Earthquakes, Volcanoes,
and Tectonics) invites you to the next instalment of our COMET webinar
series, viewable from the home office.

*The origin of stress- and fluid-driven seismicity in volcanic settings: a
laboratory perspective*

Dr Philip Benson (University of Portsmouth)

*Wednesday 9th March 2022 at 4pm UK time* (4pm UTC / 5pm CET / 8am PST)

*Please register at: *
https://urldefense.com/v3/__https://universityofleeds.zoom.us/webinar/register/WN_n0PqDx2vQNC23vpWeuImaw__;!!IKRxdwAv5BmarQ!KtIuUrPWm496kuwWXcBW33sYbtbIUvop9W84-W4wdTUCDrP7B6gP8MDamV9VH5s$ 
<https://urldefense.com/v3/__https://universityofleeds.zoom.us/webinar/register/WN_n0PqDx2vQNC23vpWeuImaw__;!!IKRxdwAv5BmarQ!OIN_6GrTZ6zMv9viOxK8O6ZCBjflVA6_n91CNFE6BR15tRHukx7akrnBYTd92bM$>

(After registering, you will receive a confirmation email containing
information on how to join the webinar)


Abstract:

Seismicity has long been used to monitor volcanoes and active volcanic
areas. In these regions, rising magma stresses the overlying rock to open
(or reopen) conduits for fluid and gas flow. The fracturing and ensuing
fluid-flow generates a range of seismicity frequently characterised by
their spectral properties. These include Volcano-Tectonic (VT) events
generated by rock fracture, Long Period (LP) seismicity generally
interpreted as indicators of fluid migration, and Hybrid events
characterized by a high frequency (VT-like) onset and low frequency
(LP-like) coda.

In many cases these data are reliable precursors to eruptions after
extended repose (volcanoes that have been quiet for 100 years or more), and
are frequently detected weeks or months before an eruption. For some years
the detection of LP events was heralded as a new and more accurate
forecasting (warning) method directly linked to fluid movement; however,
this has proven inconclusive.

To decipher these signals, and better constrain their physical generation
mechanisms, laboratory rock physics experiments simulating these different
seismic sequences have been developed. Here, I present data from triaxial
rock deformation experiments collected over ~15 years and from a range of
rock types and pressure/temperature conditions. Collectively, they suggest
that Hybrid events are more likely to be generated when fluid is present,
and that LP events are enhanced by elevated temperature conditions due to
localized fluid phase change. However, recently published work has now also
shown that a common low-cohesion volcanic sediment from Campi Flegrei
caldera (Italy) produces Long Period and low frequency seismicity whilst
undergoing deformation in dry conditions rather than solely fluid-saturated
conditions, with implications for interpreting upper edifice stability and
hazard from seismic sequences.



Catch up on past COMET and COMET+ webinars on our YouTube page:
https://urldefense.com/v3/__https://www.youtube.com/channel/UCtFDytX1hgjvlS4NH48M2oQ/video__;!!IKRxdwAv5BmarQ!KtIuUrPWm496kuwWXcBW33sYbtbIUvop9W84-W4wdTUCDrP7B6gP8MDa_pBIrXw$ 
<https://urldefense.com/v3/__https://www.youtube.com/channel/UCtFDytX1hgjvlS4NH48M2oQ/videos__;!!IKRxdwAv5BmarQ!OIN_6GrTZ6zMv9viOxK8O6ZCBjflVA6_n91CNFE6BR15tRHukx7akrnBJA2PZD8$>




Best wishes,

Scott Watson & Tamarah King



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