Meetings in Chile, March 4-12, 2013
related to the
Maule Aftershock Workshop and GRO-Chile Network
David Simpson, IRIS, April 10, 2013
Maule Aftershock Workshop
University of Concepcion, Chile, March 4-8, 2013
Organizing Committee:
Sergio Barrientos
Klaus Bataille
Susan Beck
Anne Meltzer
Onno Oncken
Andreas Rietbrock
Ray Russo
Frederik Tilmann
Christophe Vigny
University of Chile
University of Concepción
University of Arizona
Lehigh University
Helmholtz Centre Potsdam
University of Liverpool
University of Florida
Helmholtz Centre Potsdam
Ecole Normale Superieure
Website - http://www.iris.edu/hq/maule_workshop/home
The primary purpose of this workshop was to bring together the international teams from Chile, US, Germany,
England and France that participated in the aftershock instrument deployment following the February 2010 Maule
earthquake. An NSF RAPID award to IRIS (EAR-1036352) supported the initial 2010 deployment of 100+
instruments for 9 months in 2010. Funds remaining in the award were used to provide student and keynote speaker
travel and limited logistic support for the workshop. Approximately 60 participants attended, including
representatives from all of the aftershock teams, a large contingent of Chilean researchers and students, and three
students from the US.
Scientific and poster sessions presented the results of studies using the portable aftershock data and showed that
a wide variety of investigations were being undertaken that extended well beyond initial event location. Hiroo
Kanamori gave a keynote presentation that reviewed recent improvements in the understanding of the styles of
rupture in large and great earthquakes. Presentations at the plenary sessions and posters are being collected and will
be made available through the workshop website. A report is being developed for publication in EOS and a
summary of the aftershock studies is anticipated for publication in Nature Geoscience or Seismological Research
Letters.
The organizational support and meeting facilities provided by the University of Conception were exceptional.
An opening ceremony at the University on Monday evening included talks by representatives of the university and
ONEMI (Chilean equivalent of FEMA) and a history of seismological studies in Chile by Armando Cisternas. Field
trips at the end of the workshop focused on uplift areas and reconstruction in coastal areas south and north of
Concepcion impacted by the earthquake.
Discussion sessions confirmed that the agreement to share and merge data from the aftershock deployment had
indeed been a great success. Data from the US, British and French stations are available through the IRIS Data
Management Center and the German data are available through GFZ Potsdam. The Potsdam, Liverpool and the
USGS NEIC have created catalogs of more than 30,000 events. Much more extensive and comprehensive analyses
had already been carried out than would have been possible from the individual data sets in isolation. The USGS has
relocated 2500 events using a multiple event location approach and determined regional moment tensor solutions for
450 events larger than m4.5. Sharing and comparing catalogs provided an important foundation for more detailed
studies of events and clusters within the aftershock zone. There is special interest in the larger aftershocks and those
that occur outside the plate interface, especially normal faulting events (~M7) in the upper plate that are of special
concern in Chile because they can have shallow hypocenters on-shore, in proximity to populated areas.
During plenary sessions at the workshop, participants identified various opportunities for future collaborative
activities:
Follow-up Workshop – Tentative plans were made to hold a follow-up workshop in 2014. In addition to
continued collaboration on research related to the Maule sequence and general Chilean seismology and tectonics,
interest was expressed in expanding the disciplinary focus to embrace engineering seismology, to extend the
April 2013 Maule Workshop and GRO-­‐Chile Status 2 geographical participation to surrounding countries in South America, and to include an educational and training
component on data collection and analysis for advanced students and early career Earth scientists.
Scientist and Student exchanges – With the continuing Chilean government interest in the Maule earthquake,
the emergence of superior data from the GRO-Chile stations and the planned expansion of the Chilean National
Network, there are significant opportunities for growth of earthquake studies in Chile and enhanced interactions
with research and academic programs at US universities. It was obvious at the Concepcion workshop that sustained
interactions with German and French organizations (GFZ, IPG, CNRS) over the past decade or more have had a
very positive impact on collaborative programs. GFZ has made significant investments in IPOC (Integrated Plate
Observatory in Chile) in northern Chile that have led to ongoing research collaborations in seismology and geodesy.
Most of the recent academic appointments at the universities in Santiago and Concepcion have come from advanced
studies in Europe, in contrast to the predominance of degrees from US universities in earlier decades. There have
been some very successful NSF-funded collaborative research programs with US universities in recent years, but
these provide little opportunity for sustained educational interactions. The US participants in the workshop
expressed interest in exploring other funding opportunities (US, Chilean or international) to encourage longer-term
engagement. There was also interest from the Chilean side in collaboration with US groups (e.g. IRIS and SCEC) on
programs for enhanced public education and outreach in Chile.
Ocean Observations – The study of earthquakes in the Chilean subduction zone is severely limited by the lack
of observations offshore, above and seaward of the trench. As the Workshop was ending, a cruise involving U.
Chile and Oregon State University scientists was leaving to recover ocean bottom seismometers (OBS), which had
been recording in the Maule aftershock region since May 2012. The data from these instruments will improve the
location of continuing aftershocks and studies of structure in the Maule zone. Monitoring of seismicity in Chile
would be greatly enhanced with continuous observations from offshore OBS, preferably in real-time from cabled
systems. Cabled offshore systems would provide significant opportunities for coordination with other geophysical,
oceanographic and biological programs gathering information on the offshore environment in Chile.
Subduction Zone Observatory – The recent growth of observational systems for seismology and geodesy
along the Pacific coast of North America (EarthScope) and in many Central and South American countries
(especially Mexico, Ecuador and Chile) could stimulate to the development of a long-term, multi-national program
based on an integrated suite of observational systems for observing plate boundary processes along the entire eater
Pacific rim, from the Aleutians to Tierra del Fuego. Establishing open data exchange, such as that initiated between
IRIS and U. Chile for the GRO-Chile stations and now being pursued with Ecuador, would be an important
component of such a network. The GFZ group working in northern Chile expressed openness to working with
additional partners in their IPOC project. Expanded collaborations with other Pacific countries in South and Central
America present various technical, financial and political challenges, but the model established with the GRO-Chile
network and the international collaboration on the Maule aftershock deployment provide an excellent framework for
exploration in other countries.
GRO-Chile Network
The ten-station network of Global Reporting Observatories in Chile (GRO-Chile) has been established as a
collaborative project between IRIS and the University of Chile’s Department of Geophysics and Seismological
Service. Equipment and support for IRIS to assist in installation and training were provided under NSF MRI EAR1040292. The stations, based on the design used for the EarthScope Transportable Array, are spaced at
approximately 300 km along the entire length of Chile and are intended to be form a backbone for the new Chilean
National Seismic Network. Each of the stations is equipped with broadband seismometers, strong motion
accelerometers, infrasound microphones and a suite of meteorological sensors. The University of Chile has agreed
to make the data from all GRO-Chile stations freely open for distribution in real time. In addition to providing
significant enhancement to earthquake monitoring for Chile, these stations provide important new data to constrain
earthquake locations throughout the Southern Hemisphere. As the network has been installed, there has been close
collaboration between IRIS, U. Chile and the USGS National Earthquake Information Center (NEIC) to ensure that
the GRO-Chile data are integrated into the NEIC global monitoring network and NEIC has provided advice and
assistance to U. Chile in the development of their national earthquake monitoring and reporting systems.
Maule Workshop and GRO-­‐Chile Status 3 GT.LPAZ
Installation of the GRO-Chile stations began in August 2011 and most stations were
(
!
operating by April 2012. Although the sensing and recording systems at individual stations
GO01
have operated well since installation, there have been significant problems in establishing
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(
stable communication links between many of the remote stations and the central receiving
system at U. Chile. Real-time telemetry of data from half of the stations has been relatively
IU.LVC
(
!
stable since installation, but intermittent problems have impacted all stations and two of the
GO02
southern stations have suffered from significant loss of real-time data. The communication
!
(
and power systems at the most northerly station were vandalized, but have since been
GO03
replaced and the station has been relocated. A service trip to all stations by an IRIS and U.
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(
Chile engineering team in March-April, 2013 is working to rectify the communication IU.LCO
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!
GO04
problems and currently 8 of the 10 stations are reliably reporting data in real time.
!
(
Approximately 3700 kilometers or 2300 miles
April 2013 In the aftermath of the 2010 earthquake, the University of Chile has been working to
G.PEL
(
!
establish a new seismological service involving both enhanced instrumentation for GO05
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(
earthquake recording and a centralized system for data analysis and earthquake reporting.
These efforts have been impeded over the past three years during on-going negotiations
between the university and ONEMI, the Chilean federal agency responsible for
GO06
emergency management. On March 27, we received word that final agreement has been
!
(GT.PLCA
(
!
reached and funding secured for support of a new National Seismological Center at the
University of Chile. This agreement and stable funding will allow the university to GO07
Locations of the ten !
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hire new personnel to accelerate the installation of more than 70 new broadband
GRO-­‐Chile stations seismic stations and 130 GPS stations and provide enhanced support for the GRO(red) and other global quality Chile stations. Instrumentation and hardware for these has already been acquired
stations in the region GO08
and sites have been established for 20 stations. An additional 297 free-field, strong(blue) !
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motion stations are also being installed by a separate agency as part of the national
GO09
earthquake observing system. It is planned that 50 of the new broadband stations
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(
will be installed within the next year.
GO10
"
Santiago
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The MRI award to IRIS for development, installation and operation of the GROChile stations is scheduled to end in August 2013. We intend to request a no-cost
extension to use remaining funds to continue to train the staff of the new National Seismological Center in operation
and maintenance, to ensure that all communication systems are hardened for long-term stable operation and to assist
in installation of GPS instruments at GRO-Chile sites. Title of the equipment provided under the MRI award has
been transferred to the University and the university provided ~$450K in cost sharing for the MRI project. An MOU
between IRIS and U. Chile provides for continued open sharing of data and long-term U. Chile support of all
operational costs for GRO-Chile stations.
US Government Interest
The US embassy in Santiago has shown on-going interest in earthquake studies in Chile and the development of
the new national monitoring systems. The embassy provided assistance in supporting the logistics for the Maule
aftershock deployment in 2010 and has played an important role in facilitating meetings between US groups,
ONEMI and the University of Chile during negotiations for the establishment of the new National Seismological
Service.
During a visit to Chile in January 2012 to visit the NSF supported astronomical observatory at Cerro Tololo,
NSF Director Subra Suresh visited the GRO-Chile station GO04, located on the observatory grounds, and toured the
seismological labs at the University of Chile.