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+