[IGSSTATION-8619] Possible co-seismic displacements: ASPA, FTNA, NIUM, SAMO, TONG

[igs-rf at ign.fr]

# Author : Paul Rebischung
# Contact : igs-rf at ign.fr
# Subject : Possible co-seismic displacements: ASPA, FTNA, NIUM, SAMO, TONG
# 
# This is a notification that recent earthquake(s) may have induced noticeable displacements of one or more IGS stations.
#
# This message and the table below were generated automatically based on the following procedure:
# * The Global Centroid-Moment-Tensor (CMT) catalog (https://www.globalcmt.org/) is scanned every day for new earthquakes.
# * For every new earthquake, the width, length and slip of the rupture are estimated from:
#    - Yen & Ma (2012; https://doi.org/10.1785/0120100046)'s scaling law if the earthquake magnitude is less than 7.6;
#    - Mai & Beroza (2000; https://doi.org/10.1785/0119990126)'s scaling law it the earthquake magnitude is larger.
#    (See justification for these choices in Métivier et al., 2014; https://doi.org/10.1002/2014JB011280.)
# * For every new earthquake, based on its estimated CMT and rupture parameters, co-seismic displacements are calculated
#   at all IGS stations using Okada (1985; https://doi.org/10.1785/BSSA0750041135)'s approach. Given that the CMT inversion
#   from seismic waves gives rise to two possible solutions for the rupture plane, two possible co-seismic displacements
#   are calculated for every station and earthquake.
# * If any calculated 3D co-seismic displacement of an IGS station exceeds 1 mm, it is included in the table below.
#
# Warning : The co-seismic displacements thus calculated rely on several coarse approximations. They should not be used as
#           estimates of the actual co-seismic displacements, but only as rough orders of magnitude.
# 
# The column "RF?" in the table below indicates whether each station is part of the current IGS reference frame (IGS20),
# hence might need to stop being used as a reference frame station after the earthquake.
# 
#__________station_________   ___________________________earthquake_____________________________   dist_   _____displacement1_____   _____displacement2_____
#sta_ lon[deg] lat[deg] RF?   date_______________ Mw_ location________________ lon[deg] lat[deg]   d[km]   dE[mm]_ dN[mm]_ dH[mm]_   dE[mm]_ dN[mm]_ dH[mm]_
#-----------------------------------------------------------------------------------------------------------------------------------------------------------
 ASPA -170.722  -14.326 Yes   2023-05-10 16:02:00 7.6 Tonga Islands            -174.610  -15.600     441      -3.6    -2.0    -1.4      -3.6    -2.0    -1.5
 FTNA -178.121  -14.308 No    2023-05-10 16:02:00 7.6 Tonga Islands            -174.610  -15.600     404      -5.2     2.7     2.2      -5.3     2.7     2.2
 NIUM -169.927  -19.077 Yes   2023-05-10 16:02:00 7.6 Tonga Islands            -174.610  -15.600     630       2.5    -2.0     0.4       2.4    -2.0     0.4
 SAMO -171.738  -13.849 No    2023-05-10 16:02:00 7.6 Tonga Islands            -174.610  -15.600     365      -6.6    -4.8    -3.7      -6.5    -4.8    -3.8
 TONG -175.179  -21.145 No    2023-05-10 16:02:00 7.6 Tonga Islands            -174.610  -15.600     619       0.5    -1.0     0.5       0.5    -1.0     0.5