strainmeter data access - unavco · or google “iris webservices url builder”!! url is built as...
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STRAINMETER DATA ACCESSKathleen Hodgkinson, UNAVCO
2016 Strainmeter Short CourseUNAVCO Science Workshop
Examine methods and tools to download raw and processed data
OVERVIEW
RAW DATA
• If you want anything other than 10 minute interval data you need to download SEED from the IRIS DMC.!
!• Web Services recommended!!• You will need to know the SEED codes for the site
SEED CODES
PB.B004.RS1.T0 !Data channels are uniquely identified by SEED code
PB = Network Code !B004 = Site Code !RS1 = Channel Code !T0 = Location Code !
PB.B004.RS1.T0 !Data channels are uniquely identified by SEED code
SEED CODES
PB = Network Code !B004 = Site Code !RS1 = Channel Code !T0 = Location Code !
PB.B004.RS1.T0 !Data channels are uniquely identified by SEED code
SEED CODES
PB = Network Code !B004 = Site Code !RS1 = Channel Code !T0 = Location Code !
PB.B004.RS1.T0 !Data channels are uniquely identified by SEED code
SEED CODES
Sample Rate !R < 1 sps !L = 1 sps !B = 20 sps !E = 200 sps !
Data channels are uniquely identified by SEED codePB.B004.RS1.T0 !
SEED CODES
Measurement !S = Strain !H = Seismic !K = Temperature !E = Voltage !
Data channels are uniquely identified by SEED codePB.B004.RS1.T0 !
SEED CODES
Orientation !N = North !E = East !1 = “not North” !2 = Perpendicular to 1 !
Data channels are uniquely identified by SEED codePB.B004.RS1.T0 !
SEED CODES
PB = Network Code !B004 = Site Code !RS1 = Channel Code !T0 = Location Code !
Data channels are uniquely identified by SEED codePB.B004.RS1.T0 !
SEED CODES
PB.B004.RS1.T0 !Data channels are uniquely identified by SEED code
Location Code !T0, TS = BSM !IR, IM, II = LSM !“blank-blank” = Seismic & Pore pressure !!
SEED CODES
RAW DATA
http://service.iris.edu/irisws/timeseries/docs/1/builder/! !OR google “IRIS webservices url builder”!!
URL is built as you type
URL is built as you type
Plot
RAW STRAIN DATARAW DATA
Change to ASCII
WEB SERVICES
The URL also forms a scriptable command,
Copy paste the command from your browser window to a terminal
ftp -o MyData.txt "http://service.iris.edu/irisws/timeseries/1/query?net=PB&sta=B004&cha=RS1&start=2014-02-01T00:00:00&end=2014-02-21T00:00:00&output=ascii2&loc=T0”
Metadata in SEED format
Metadata in SEED format
PROCESSING METADATABefore we can combine the gauge data we need to know the orientations, gauge weightings and scale factors i.e., the calibration matrix.
This can be found in the XML file or README file available from UNAVCO.
f t p : / / b s m . u n a v c o . o r g / p u b / b s m / l e v e l 2 / B 0 7 3 /B073.README.txt
PROCESSING METADATAProcessing metadata includes
• Linearizing information
• Calibration matrix
• Barometric response coefficients
• Tidal phase and amplitudes
• Filter coefficients
TENSOR STRAINLEVEL 2 README FILE
DOWNLOADING LEVEL 2 DATA
-126˚ -124˚ -122˚46˚
48˚
100 km
B018
7
Tremor from http://www.pnsn.org/tremor
27 3 10 17 24 31 7 14July 2014 August 2014 September 2014
Tremor Event September 2014 Shear Strains Recorded by B018, Washington
-100
-50
0
50
100
27 3 10 17 24 31 7 14
27 3 10 17 24 31 7 14July 2014 August 2014 September 2014
Eee-Enn
2Ene
nano
strain
Plotting an ETS event
ftp://bsm.unavco.org/pub/bsm/level2/delphi018bor2006/
Level 2 Processed data
XML or flat ASCIIProcessed data
DOWNLOADING LEVEL 2 DATA
LEVEL 2 STRAIN DATA
File naming convention enables download via cron.
LEVEL 2 README FILE
LEVEL 2 STRAIN DATA
Gauge areal and shear strains within each tar file• B018.2010.xml.gauge0• B018.2010.xml.gauge1• B018.2010.xml.gauge2• B018.2010.xml.gauge3• B018.2010.xml.2Ene• B018.2010.xml.Eee-Enn• B018.2010.xml.Eee+Enn
Gauge Data
Areal Strain
Shear Strain
LEVEL 2 STRAIN DATA
Gauge areal and shear strains within each tar file• B018.2010.xml.gauge0• B018.2010.xml.gauge1• B018.2010.xml.gauge2• B018.2010.xml.gauge3• B018.2010.xml.2Ene• B018.2010.xml.Eee-Enn• B018.2010.xml.Eee+Enn
Gauge Data
Areal Strain
Shear Strain• Edited• Quality marked• Ready for analysis
• Estimates tidal amplitudes and phases.!
• Determine the ‘‘drift’’ or ‘‘trend’’ and calculate its power spectrum using an ARMA model.!
• Includes in its modeling the effect of partially correlated data, such as atmospheric pressure.!
• Interpolates missing data!
• Performs a rough search for abnormal data.!
BAYTAP08Tamura, Y., Sato, T., Ooe, M. and Ishiguro, M. (1991), A procedure for tidal analysis with a Bayesian information criterion. Geophysical Journal International.
http://igppweb.ucsd.edu/~agnew/Baytap/baytap.html
−0.4
−0.2
0.0
0.2
01 08 15 22 29 01 08 15 22 29 01 08 15 22 29July 2014 August 2014 September 2014
B018.2Ene.decomp.txt noise
nano
strain
540
560
580
600
620
640
01 08 15 22 29 01 08 15 22 29 01 08 15 22 29July 2014 August 2014 September 2014
B018.2Ene.decomp.txt Drift
nano
strain
−4
0
4
01 08 15 22 29 01 08 15 22 29 01 08 15 22 29July 2014 August 2014 September 2014
B018.2Ene.decomp.txt Barometric Response
nano
strain
−20
0
20
01 08 15 22 29 01 08 15 22 29 01 08 15 22 29July 2014 August 2014 September 2014
B018.2Ene.decomp.txt Tide
nano
strain
BAYTAP08
SPOTL
Agnew, D. C. (2012). SPOTL: Some Programs for Ocean-Tide Loading, SIO Technical Report, Scripps Institution of Oceanography,!
Agnew, D. C. (1997). NLOADF: a program for computing ocean-tide loading, J. Geophys. Res.,102, 5109-5110.!
!
http://igppweb.ucsd.edu/~agnew/Spotl/spotlmain.html!
!
SPOTL: Some Programs for Ocean-Tide Loading
Allows the computation of:• the solid Earth tides• the load tides produced on the solid Earth by the ocean tides• combination of solid Earth and ocean load• calculates strains, tilt and displacement.!
SPOTLSPOTL: Some Programs for Ocean-Tide Loading
BAYTAP08 calculate tides, SPOTL to predict tides!
Langbein, J. (2010), Computer algorithm for analyzing and processing borehole strainmeter data, Comput. Geosci., 36(5), 611-619, doi:10.1016/j.cageo.2009.08.011.!
CLEANSTRAIN+CleanStrain+
Considers the temporal correlation of strainmeter data. Estimateso terms that describe the underlying error model, o the tidal terms, o the pressure loading term(s), o amplitudes of offsetso rate and changes in rate, and o the amplitudes and time constants of either logarithmic or exponential curves that
can characterize postseismic deformation or diffusion of fluids near the strainmeter
CLEANSTRAIN+CleanStrain+