Wir sind Helden and the earthquake experiment

My new favourite band are a German language band called Wir sind Helden. When they played the Rock am Ring festival in 2007 they were part of a seismic wave experiment. Part way through the concert, they had the crowd of 50,000 people jumping up and down in time. There were seismographs at different distances from the site. My German isn't yet that good but I get the impression that they didn't detect much. But they were trying to answer the question about what would happen if everyone on Earth jumped at the same time as part of a popular science programme on WDR. I've done that calculation before and the answer is - er, nothing! See the concert at https://www.youtube.com/watch?v=_rcU6elIIFg Read about it at erdbeben-experiment-50000-huepfer-liessen-die-eifel-beben-590408