article_snippet.sent: During this time, two seismic events with magnitudes of 6.9 and 7.1, took place on 3 March and 20 March.
article_snippet.sent: But the largest hum coincided with the strongest seismic waves during the Johanna storm on 10 and 11 March.
article_snippet.sent: That storm generated waves with a peak period of 16 seconds that reached heights of up to 42ft (12.8 metres).
article_snippet.sent: During That storm, a spectrogram found energy levels reached 10 mHz, and lasted 36 hours.
article_snippet.sent: By looking at how much energy was generated by That storm, the researchers were able to conclude that the hum was caused by That storm, and wasn't the remnants of seismic activity from the events.
article_snippet.sent: During March 2008 two large seismic events took place.
article_snippet.sent: But the largest hum  coincided with a Johanna storm (right).
article_snippet.sent: That storm generated waves with a peak of 16 seconds and heights of 42ft (12.8 metres) (left).
article_snippet.sent: From this, the team could conclude the largest hum   was caused by That storm, and not leftover from the seismic events .