Dramatic underground plate motion at SMCO, Snowmass, Colorado, USA

The seismogram of SMCO, Snowmass, Colorado, USA, in REV

http://rev.seis.sc.edu/stations/?zip_or_station_code=IW.SMCO

showed a normal ground motion wave before May 18, 2014.

On May 18, the ground motion has begun to change between 5:00 and 6:00,

then, a big ground motion, Phase 1, with a lot of big undulations and a large number of spikes-formed movement started suddenly at around 8:30 and lasted seven hours.

[Phase 1: May 18, 8:00 - 16:00]

On the next day, May 19, another big ground motion of Phase 2 appeared at around 7:00 and lasted one hour until 8:00. The strength of the motion change of Phase 2 was bigger than that of Phase 1.

[Phase 2: May 19, 7:00 - 8:00]

The next big ground motion of Phase 3 began at 8:00 with Phase 2 continuously , and it lasted two hours. The strength of the motion change of Phase 3 was bigger than that of Phase 2.

A big ground motion of Phase 4, the strength between Phase 2 and Phase 3, appeared twice afterwards, Phase 4-1 and Phase 4-2.

A Phase 4-1 appeared from 23:00 of May 19 to 2:00 of May 20 and a Phase 4-2 appeared from 6:00 to 9:00 of May 20.

After Phase 4-2, Phase 5 which was the highest strength ground motion of the five appeared at 12:00 of May 20 and lasted for an hour.

From around 15:00 of May 20, a few hours after the ending of Phase 5, a seismogram was unavailable for 24 hours. It was shown at 15:00 of May 21 again. The line indicating a ground motion has begun to greatly rise from a base line.

When watched data screen every forwarding for two hours, the magnification of the seismogram gradually became small because a line indicating the ground motion greatly fluctuated up and down or a line greatly slipped off from a base line, which means the magnification of a seismogram showing for 24 hours in REV is regulated automatically in response to the biggest motion change in that time.

A line of ground motion in 24 hours has been displayed with low magnification almost everyday since May 21.

I show two kinds of a 24-hour image, one is from 0:00 to next 00:00, the other is from 12:00 to next 12:00, to compare the magnification by overlapping the time by 12 hours.

A figure below is from 2014/05/17 to 2014/06/08.

A dramatic underground plate motion at SMCO, Snowmass, Colorado, USA, began on May 8, 2014, and it has continued since then, as of 2014/06/08.

Please note there was a 4-mile mudslide in Colorado on May 25

4-Mile Mudslide in Colorado With Little Rain

when one of the biggest ground motion was monitored at SMCO station.