# Data Services Products: Surface-Wave Radiation Patterns – Interactive Plots

## Summary

The surface-wave radiation pattern depends on the source process and therefore on the components of the moment tensor, on the depth of the earthquake, and on the frequency of the seismic waves. This website calculates the radiation pattern for any combination of these variables for both Rayleigh and Love waves. Further ExplanationsThe radiation patterns are displaying spectral amplitudes in [m/Hz] which have been calculated for continental lithosphere using the Earth model iasp91. Due to its discontinuities at 20 and 35km, the radiation patterns change abruptly at these depths.

The focal mechanisms for the earthquakes have been obtained from the Global CMT Project. We assume the event origins to be point sources in space and time and hence, all radiation patterns have a vanishing half-duration and directivity is not taken into account.

In accordance with the Global CMT Project, the moment magnitude is calculated for the double-couple component of the moment tensor only and will hence be smaller than expected for moment tensors with large isotropic components.

 Earthquakes Random Source Earthquakes with Mw (GCMT) ≥ 8.0
Frequency [Hz]
Moment Tensor
 Mrr = Mtt = Mpp = Mrt = Mrp = Mtp =
 Exponent = Nm
Moment Magnitude
Mw = 8.0
Depth [km]

## Calculator of Moment Tensor Components

Pure doule-couple sources may be described by the strike, dip and slip angle of the fault on which the earthquake occurs. This calculator may be used to calculate the moment tensor components for pure double-couple sources and their surface-wave radiation patterns.

Fault Geometry
 Strike = Dip = Slip =

 Mrr = 0.0 Mtt = 0.0 Mpp = 0.0 Mrt = 0.0 Mrp = 0.0 Mtp = 0.0

## Citations and DOIs

To cite the source of Surface-Wave Radiation Pattern product:

• Rösler, B., and S. van der Lee (2020). Using Seismic Source Parameters to Model Frequency‐Dependent Surface‐Wave Radiation Patterns. Seismol. Res. Lett. 91, 992–1002, doi:10.1785/0220190128.

To cite the Wave Radiation Patterns Data Product or reference use of its data:

To cite the IRIS DMC Data Products effort:

• Hutko, A. R., M. Bahavar, C. Trabant, R. T. Weekly, M. Van Fossen, T. Ahern (2017), Data Products at the IRIS‐DMC: Growth and Usage, Seismological Research Letters, 88, no. 3, https://doi.org/10.1785/0220160190.

## Credits

This product was sponsored by Integrated Data-Driven Discovery in Earth and Astrophysical Sciences (IDEAS) program, a National Science Foundation Research Traineeship (NRT) program at Northwestern University.

• Boris Rösler, Northwestern University (Concept and Programming)
• Frank Elavsky, Northwestern University (Programming)
• Suzan van der Lee, Northwestern University (Concept)
• Emily Wolin, Northwestern University (Idea)

## Contributors

Boris Rösler (boris@earth.northwestern.edu)