Emmy-Noether-Project "Bridging Geodesy and Seismology"

Activities

Summer Hack 2016

Our group members at the Hack.
Impressions from the first BridGeS pyrocko hack weekFotos: H. Sudhaus

 

Summary

In the Summer 2016 we had our first group Kick-Off Hack Week at GFZ Potsdam. The BridGeS group had started to form with the fresh Msc Geophysics Andreas Steinberg as PhD and Msc Geophysics Marius Isken as our second software developer. These new members together with long-time colleagues Hannes, Sebastian and Henriette are discussing the state-of-the-art of our software analysis tools. In one room, for a whole week, with many snacks and litres of Mate softdrinks. Can this be the preferred 'project retreat' format for our project?

In this week the main goals have been to bring everyone on a good common information level, to outline and agree on the goals in the to-be-developed new modelling techniques combining InSAR data and seismological data, and a first listing of software tool requirements. Pyrocko so far is a seismology toolbox and needs to learn working with static displacements.

Participants (in order of appearance in the foto collage): Andreas Steinberg (CAU), Hannes Vasyura-Bathke (KAUST), Marius Isken (CAU), Sebastian Heimann (GFZ), also Marius Kriegerowski and Henriette Sudhaus

 

Ideas and products of the week in some more details

The forward-side of things:

  • Source models: We optionally enable a rectangular finite source model that is defined by uniform slip instead of uniform moment. Things to do are i) to revive the Eikonal source and ii) enable edge-slip-tapering, e.g. from a uniform stress-drop assumption
  • Targets: For the InSAR displacements we need a new type of target that is static, has the five pyrocko coordinates, has a time frame attribute, SAR line-of-sight angle information and data error variance-covariance information. To prepare and handle InSAR targets we want an in-house modul for basic visualization and target preparation (filtering, subsampling, etc).
  • Green's function store: We want to implement new Green's function methods for the static data bases for layered media. THE candidate is R. Wang's PSGRN.
  • Engine: Our engine to compile dynamic and static synthetic displacements needs to learn new static targets. Also, it needs to be more efficient to make things fast.

The backward-side (inverse) of things:

  • Misfit function: We want to have data error covariance for the seismic trace as well. We test robust and fast ways to get pre-event noise statistics.
  • Sampler: Sebastian introduces Grond and we all agree that the concept is very promising and that we want to further develop it. We want to make it Bayesian.

 

Autumn Hack 2016

Showing group members discussing at the Hack.Impressions of the BridGeS Autumn Hack 2016 Fotos: H. Sudhaus

 

Here we are again for the second concentrated pyrocko action week. Yes, we find we like this format a lot! Nobody wants to miss a thing, so even Hannes joins us for many hours via telecommunication from desert lands. We share and discuss our ideas, problems, questions and Mate softdrinks. Sometimes we even have solutions and answers - or coffee (in rare cases Jaegermeister).

Main topics are the static Green's function store, performance of forward calculations, code health with new tests and documentation.

Important developments in some more detail:

  • Kite is born: The in-house InSAR data post-processing module kite outlined during the Summer Hack has been set-up by Marius. It is very interactive, handy and generally very promising. Further development will bring great things!
  • Pyrocko and new modules: Pyrocko has now some special modules for special purposes. We decide to organize all of them under pyrocko.org to emphasize the strong connection and interactiveness of the modules with mother pyrocko.
  • Performance: Sebastian shows us how to speed up the code by moving some functions to C code. Here we are truly hacking - or at least some of us).
  • PSGRN GF store: Hannes is working further bringing the PSGRN functionality to pyrocko. The group tries to help.
  • Documentation: We start to look into documentation of the code. This ia a long-term engagement

 

Participants are again: Marius Isken, Sebastian Heimann, Hannes Vasyura-Bathke (webcam), Andreas Steinberg, Marius Kriegerowski and Henriette Sudhaus (bottom picture left to right).

Winter Hack 2017

Dummy image
On the frozen Heiligensee in Potsdam during our third Hack Week - Hacking where others go on holiday.Foto: kind local lady on skates

 

Planned as a Go-Away-Winter-Hack, we finally admitted that some winter days can indeed be very enjoyable - like here on the Heiligensee in front of the Marble Palais in Potsdam. A perfect welcome for our new group member Simon, who here has just started his PostDoc with us.
During this hack we enjoy and discuss not only sun and ice, but mainly the new pyrocko functionalities that have been finalized since the last week. Together we work on example scripts and documentations. We also start discussions on new goals with our new expert Simon on slow slip or interseismic motions.

Achievements made so far:

  • Speed: With new function architecture and C code extensions we increased the forward calculation of seismograms a lot. Also the new psgrn static store back end is very fast. We are ready for optimizations! Also, we want to add fast analytical function for elastic half-space medium. Good for tests.
  • SatelliteTarget and Statictarget: are new handy target types for InSAR and GPS data in pyrocko.
  • New webpage: We have a shiny new project webpage pyrocko.org. Now we need to work hard to populate it with example scripts and improve the documentation everywhere.

Further topics:

  • Joint targets: the pyrocko engine will be enabled to handle heterogenous targets.
  • SatelliteMisfitTarget: A to be introduced class in pyrocko for optimizations
  • slow slip and back slip: We discuss what is special for dealing with aseismic slow slip and how locked fault in interseismic times are implemented.
  • Joint optimization with Grond: we want to teach grond to optimize also static targets. We discuss needs.

 

Participants: Henriette Sudhaus, Simon Daout, Sebastian Heimann, Andreas Steinberg, Marius Kriegerowski, Marius Isken (from left to right, see picture) and Hannes via telecon again from desert land.

Group visit to Comet, Leeds

Activites with group members and colleagues from Leeds in Leeds.Going out with tools and colleagues - we present and discuss pyrocko with our project partners at Leeds university. Fotos:H. Sudhaus & S. Daout

 

We are kind of ready to present the new tools to an interested crowd of expert colleagues and future users at Leeds university. This is a first test out-of-house for the new InSAR tools and not everything is working perfectly, of course. Work and after-work-pleasure are quite intense. Here, we get a lot of critical and positive feedback, new ideas and we outline the future cooperation.

Geofon

SRCMOD Database