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”.
August 9, 2020 at 11:38AM