International Polar Year 2007–2008 - WMO

Spatially extensive new observatory networks
scientifically, targeted new local stations, and
upgrades and ongoing maintenance of pre-IPY
instrumentation all contributed to the data collection
during IPY. The most spectacular advances in network
coverage occurred in Greenland and in Antarctica (Fig.
2.8-7) where extensive deployments of autonomous
stations at remote sites have been completed. In
these regions alone, over 175 remote observatories
were installed during the IPY years and 28 nations
contributed to the Antarctic and Arctic POLENET
effort. More detailed information on the range of
activities and national contributions to the program
is provided on the POLENET web site (www.polenet.
org).
In Greenland (Fig. 2.8-7d), a U.S.-led effort carried
out in collaboration with Denmark and Luxembourg
installed 46 new continuous GPS sites in a network
called GNET (Greenland GPS Network) that completely
surrounds the bedrock margins of Greenland (Bevis
et al., 2009b). Seismic efforts, led by Denmark,
continued in Greenland through the IPY and a new
internationally-coordinated seismic network, called
GLISN (Greenland Ice Sheet Monitoring Network), will
deploy new, co-located, autonomous seismic and GPS
stations in the coming years (Anderson et al., 2009).
In Fennoscandia, the LAPNET (Lapland Network)
project deployed ~35 broadband seismometers,
complementing existing continuous GPS stations
and permanent seismic stations, led by Finland in
collaboration with several European nations and Russia
(Kozlovskaya and Poutanen, 2006). The HuBLE (Hudson
Bay Lithospheric Experiment) overlapped with IPY
activities and seismic data from an array of 35 broadband
seismometers is providing a data set across part of arctic
Canada, with science objectives highly complementary
to the POLENET IPY programme (www1.gly.bris.
ac.uk/~jmk/HuBLE/home.html). Elsewhere across the
Arctic, geodetic and seismic infrastructure maintained
by Canada, Denmark, Finland, Norway, Sweden, Russia
and the U.S.A. form an important backbone network
providing data from regions surrounding the new,
embedded network deployments.
In West Antarctica (Fig. 2.8-7c), the ANET (Antarctic
GPS and seismic Network) project led by the U.S. in
collaboration with Canada, Chile, Germany, Italy,
Ukraine and the U.K. has installed a network of 29
new continuous GPS and 34 new continuous seismic
stations, 18 of which are co-located. Three additional
co-located stations and five additional continuous
GPS stations will be installed (Fig. 2.8-7c). Additional
components of this network on the Antarctic
Peninsula include nine new continuous GPS on
bedrock from the U.K. CAPGIA (Constraints on Antarctic
Peninsula Glacial Isostatic Adjustment) project, six new
continuous GPS on bedrock from the U.S.-led LARISSA
(Larsen Ice Shelf System, Antarctica) project and new
seismic installations by LARISSA and Spain. Other new
continuous GPS stations were installed by Germany/
Russia and by Italy to expand the network (Fig. 2.8-7c).
In East Antarctica, the GAMSEIS network
(Gamburtsev Antarctic Mountains Seismic Experiment),
also a component of the AGAP (Antarctica’s Gamburtsev
Province) IPY program, led by the U.S. in collaboration
with Australia, Canada, China, , Italy, Japan and U.K.
(Kanao et al., 2007a,b; Heeszel et al., 2009; Leveque
et al., 2010), installed a network of ~40 broadband
seismometers on the East Antarctic Ice Sheet (Fig.
2.8-7c). Additional seismic and geodetic installations
also took place at inland stations (Leveque et al., 2008;
Lombardi et al., 2009).
In addition to these new installations, an essential
component of the POLENET programme includes
continuously-recording geodetic and seismic stations
that existed prior to the IPY period (Figs. 2.8-7a and
2.8-7b). These stations contribute data in sectors of
the Arctic and Antarctic that are essential to achieve
systems-scale polar data coverage. Some stations,
for example Japan’s Syowa Station, maintain a critical
infrastructure of geodetic measurement systems that
supplement GPS. Repeat measurements at absolute
gravity stations and related gravity studies are another
important POLENET IPY effort in Antarctica (Makinen
et al., 2007, 2008; Rogister et al., 2007; Doi et al., 2008).
The network of tide gauges in the Antarctica and
Arctic provides important data for global sea-level
estimates (Craymer et al., 2006; Watson et al., 2008).
Research outcomes
Seismic and geodetic data must be acquired
over a substantial time span for robust analysis to
be possible. Data collected during the IPY years is
currently undergoing initial analysis; results will be
forthcoming over the next few years. Here, selected
s C I e n C e P r o g r a m 281