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GeoNet / fdsn

FDSN Web Services
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Events missing from quakesearch #211

Closed segburg closed 2 years ago

segburg commented 3 years ago

Hi, I noticed that some earthquakes obtained through a fdsn request were missing from the quakesearch result when using the same criteria. The discrepancy seems to kick in from 2015 (see attachment). I extracted earthquakes of M2+ and regional boundaries 163.,-50,183,-32 starting in 2000.

Looping over the years, my quakesearch was: curl -o quake-M2+${t1}-${t2}.csv 'https://quakesearch.geonet.org.nz/csv?bbox=163.,-50,183,-32&startdate='${t1}'-01-01&enddate='${t2}'-01-01&minmag=2'

The corresponding fdsn search was: curl -o $dirout/quake-W1fdsn-M2+-${t1}-${t2}.txt 'https://service.geonet.org.nz/fdsnws/event/1/query?minlat=-50&maxlat=-32&minlon=163.&maxlon=172&starttime='${t1}'-01-01&endtime='${t2}'-01-01&minmagnitude=2&format=text' .... and repeated for minlongitudes up to 180 degrees because of the annoying limitation on earthquake numbers.

missing_eqs_2015_2020.txt

bpeng commented 3 years ago

I had a quick check, seems the missing quakes are either deleted or outside the bbox (e.g. event 2015p777461 at -174.7763214, -14.7187624), QuakeSearch doesn't return deleted quakes while fdsn may not have that condition. @segburg @sue-h-gns

segburg commented 3 years ago

  1. Would you be able to investigate whether fdsn includes earthquakes that were entirely deleted? This is important to know as our earthquake catalogue needs to be complete and shouldn't include extra events. Which search should I trust?

  2. Can you explain why some of the earthquakes would be outside the bounding box when the defined bounding box was the same in the quakesearch and the fdsn search. Both results should depend on the preferred hypocentre location I would think?

salichon commented 3 years ago

@segburg Kia Ora QuakeSearch doesn't return deleted quakes --> yeap cos they are not quakes :) Quake serach is only made for the earthquakes so it s a service that is providing a subset of the large "events" data set

salichon commented 2 years ago
sue-h-gns commented 2 years ago

@salichon please take a look at my version, as it allows you to remove the deleted quakes. Several are also "outside of network interest) there are only 6 in this list that may be an issue. I will look into this further MissingFDSN2QsearchEq.xlsx

sue-h-gns commented 2 years ago

Quakes are deleted or outside of network interest.