Around the world seismic measurements were quieter during lockdown

Something that marks how strange times are, was that in March and April, a group of seismologists found seismic activity fell by 50% at 185 stations around the world (at least in certain high frequency bands from 4 – 14 Hz). For example the three graphs below show seismic activity in Brussels, Barbados and New Zealand. A slight downturn happens at Christmas but the lockdown period fell far below that.

For the first time seismologists could identify small quake signals they had missed before.

Co-author Dr Stephen Hicks, from Imperial’s Department of Earth Science and Engineering, said: “This quiet period is likely the longest and largest dampening of human-caused seismic noise since we started monitoring the Earth in detail using vast monitoring networks of seismometers.

Who knows what they might figure out now they have a handle on human background “noise”.

(B) Lockdown effects in hiFSAN compared with audible environmental noise and independent mobility data in Brussels, Belgium. (C) Lockdown effect in Barbados compared to noise levels in the last decade (in gray) and correlation with local flight data at the Grantley Adams International Airport (TBPB) (24). (D) Lockdown noise reduction recorded on borehole seismometers in […]

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August 9, 2020 at 11:38AM

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