[time-nuts] UTC and leap seconds

[jimlux]

Hal Murray wrote:
> [Chile quake]
> 
>>>    Graph of position (3 meters!):
>>>      http://ivsopar.obspm.fr/earth/tigo
> 
>> 3 meters in one direction and 60 in another.
> 
> Just to make sure we are all on the right track, the scale on the graph is 
> cm, so the motion was 300 cm West and 60 cm South.
> 
> I may have confused things by translating 300 cm to 3 m.  My head doesn't 
> normally use cm but I can quickly grasp 3 meters.
> 
> 
> 
> 
That's not all that big a displacement for that size earthquake, 
although the location is a ways from the epicenter.
Here's a map:
http://www.gpsworld.com/government/mapping/news/map-chilean-earthquake-coseismic-displacement-derived-gps-data-9667


The local 1992 Landers quake (mag 7+) had a displacement of some 5-6 
meters horizontally and 2m vertically.  Imagine sitting in a car on a 2 
lane road, and 30 seconds later, the road in front of you is displaced 
the width of the road, so you're looking at no road.  This one has been 
studied a lot because there's a whole raft of precision geodetic 
measuring points near it, as well as experimental satellite 
interferometric SAR data, etc.