ORFEUS
Seismological data in Europe – sharing high quality data
Reinoud Sleeman
Torild van Eck
Gert Jan van den Hazel
Alessandro Spinuso
Luca Trani
Niels Steenbakker
&
Virtual European Broadband Seismic Network Consortium (VEBSN)
www.orfeus eu.org
Organizations and Research Facilities for European Seismology
ORFEUS is the European non profit foundation that aims at co ordinating and promoting
digital, broadband (BB) seismology in the European Mediterranean area.
Short introduction on seismic data acquisition
Networking European seismic data exchange
Data Quality at ORFEUS Data Center
Challenges
Modern seismograph system
sensor, 3 C
(GPS) timing
datalogger
communication
archiving,
processing,
analysis
GPS
Seismic vault “Heimansgroeve” Netherlands, Limburg
Temperature
stability
ADSL
Local acquisition and archive
Quanterra Q330 datalogger
SOH
Calibration
electronics
Vacuum
glass bell jar
North
STS 1 VBB sensors (Z,N,E)
Low noise
environment
Some considerations with respect to a seismic station
• type of sensor and datalogger (characteristics, described by
metadata: poles, zeros, gain, digital filters)
broadband sensors (usually) have a flat response w.r.t. ground velocity (over a broad
frequency range); Counts to m/s2 conversion; filter charateristics
• local conditions
local noise sources (anthropogenic, wind, moving water, etc.); GPS reception;
data quality
• overall installation (technique)
thermal insulation, magnetic shielding; sensor orientation (declineation)
• communication (protocol)
latency, data completeness (gaps)
• data quality monitoring tools
ODC
ODCdoes
doesnot
notown,
own,operate
operateor
ormaintain
maintainseismic
seismicstations
stations
GFZ
Potsdam
ETH
Zurich
INGV
Rome
IPGP
IRIS
Others:
Munich
Hannover
Paris
~ 1000 stations, ~100 TB
Distributed, heterogeneous waveform data archives
EIDA – European Integrated Data Archive (ArcLink)
IT challenges:
efficient algorithm to locate the highest quality data (QC parameters)
data provenance
ODC
Services
Data
ODC
EIDA
Challenge: usage of QC parameters in the services
Quality Control information:
SOH: system performance data provided by datalogger;
logrecords/files (clock status, boom position, clock quality, input
power, …); heterogeneous, no standards
communication related:
e.g. latency (current time – time value last collected sample),
relevant for network operators, less for researchers
parameters extracted from waveform data (time series):
offset, overlap, gap, availability, RMS, mean, spikes, timing quality, …
(e.g. SC3)
QC parameters based on waveform + metadata:
Power Spectral Density (PSD, PDF)
automated seismic analysis (data processing to provide earthquake
parameters e.g. location, origin time, source mechanism;
station time residuals, station magnitude residuals, polarity …)
(e.g. Antelope, SC3, EarthWorm …)
Quality Control information:
research community tools:
synthetic tides vs. observed (tidal harmonic M2: 12h25m)
(waveform data + metadata)
long period (~ 100 sec) e.q. waves vs. observed (Ekstrom)
metadata, sensor orientation
QC communication – latency map & history (DB)
• configurable tool
for network operators
• timely alerts
latency
• in progress
time
QC parameters extracted from waveforms (SC3) – viewer, DB
offset, overlap, gap, availability, RMS, mean, spikes, timing quality, …
QC parameters based on processing (Antelope)
• magnitude residuals (per station)
• phase arrival time residuals (per station)
X
QC – Power Spectral Density (waveform data + metadata)
PSD versus time
monitor changes in behavior of seismic system
malfunctioning of seismic instrumentation
verifying and monitoring changes in meta data
changes in local site conditions
long term stability
dB
PSD at selected frequencies
Julian day
QC – Power Spectral Density versus Time
New sensor + digitizer
QC – Power Spectral Density versus Time
Example 1
Unknown
QC – Power Spectral Density versus Time
New temperature isolation sensor
Example 4
QC – Power Spectral Density versus Time
Example 4
QC – Power Spectral Density Stack (PDF)
dB
high noise model
low noise model
Period (sec)
Period (sec)
Tool to select stations for specific studies; example …
The “Earth’s Hum” ( continuously excited
fundamental spheroidal oscillations of the
Earth; 3 – 7 mHz ) can only be observed at
the quietest stations.
NL_HGN_BHZ
Courtesy Rudy Widmer
NL_WTSB_BHZ
PQLX client: interactive PSD selection tool to select a PDF subset and to
display the corresponding waveform data.
IT challenge: PQLX client webservice
QC – polarization analysis / verification
Z
N
E
rotation angle
sensor orientation
QC – research community algorithms/tools
datalogger change
Z
gain
year
N
E
courtesy: G. Ekstrom
year
QC – research community algorithms/tools
IT challenge: algorithm implementation
ORFEUS Data Center Processing / Quality Control
Antelope
Antelopeprocessing
processing
SC3
SC3QC
QCmonitor
monitor
Polarization
Polarizationverification
verification
Magnitude
Magnituderesiduals
residuals
Data
Datalatency
latency
Time
Timeresiduals
residuals
PSD
PSDvs
vsTime
Time(PSD
(PSDtimeline)
timeline)
PQLX
PQLX
Instrument
Instrumentresponse
response
Data
Datacompleteness
completenessmonitor
monitor
Services: PQLX WS
PQLX
webservice interface
(FDSN standard level)
workflow layer
interfaces to storage systems
PQLX
DB
data repositories
EIDA
FDSN