MSNoise-SARA

The Amplitude Ratio plugin for MSNoise - Bringing SARA (Taisne et al 2011) to MSNoise

Seismic amplitude ratio analysis (SARA) has been used successfully to track the sub-surface migration of magma prior to an eruption at Piton de la Fournaise volcano, La Reunion. The methodology is based on the temporal analysis of the seismic amplitude ratio between different pairs of stations, along with a model of seismic wave attenuation. This method has already highlighted the complexity of magma migration in the shallower part of the volcanic edifice during a seismic crisis using continuous records. We will see that this method can also be applied to the localization of individual earthquakes triggered by monitoring systems, prior to human intervention such as phase picking.

Temporary Documentation

Installation

• Follow the MSNoise installation instructions (here)
• Install bottleneck using either conda: conda install -c conda-forge bottleneck or pip: pip install bottleneck
• Install MSNoise-SARA

Running MSNoise-SARA

In a new or current MSNoise project, once the station table has been populated and the archive scanned:

• msnoise config set plugins=msnoise_sara is equivalent to going in the web Admin and setting the plugins configuration bit. Note the underscore and not a dash.
• msnoise p sara install will set up the MSNoise-SARA database tables and
  • automatically create the SARA_ENV jobs if the database already contains CC jobs.
  • if your DB doesn't yet contain CC jobs and you only want SARA_ENV jobs, simply run msnoise new_jobs --nocc
• msnoise p sara envelope will compute the envelope of the signal for all available data
• msnoise p sara ratio will compute the ratio of the envelopes for each pair of stations (only for common data, of course)
• msnoise p sara plot ratios will plot the ratios of all station pairs.