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Figure Above: Shooting seismics in Adventdalen in 2011, using dynocord as explosive source. 

Figure left: Bedding surfaces, in depth, in the Ad-
ventdalen area, showing the main geological units 
identified in the well Dh4 (located as black line) and 
linked to the seismics. 0m is ground surface. From 
Bælum et al. (2014).

Figure b


Map view of Adventdalen and seismic networks;
• yellow triangles - broadband seismic stations
• red circles - microseismic network at the CO2 Lab site

Seismic imaging: 


In Phase 1 of the project several regional seismic lines were acquired under the supervision of the University of Ber-
gen, as described in Bælum et al. (2012). In subsequent years focus has been on micro-seismicity during well-testing.

Microseismic monitoring network 

A comprehensive microseismic monitoring network is installed at Longyearbyen CO2 Lab and a 3D velocity model has 
been created from various independent sources of data. The results achieved from shear wave reflection seismics 
opens new feasibilities for shallow subsurface exploration with high-resolution in artic regions. The velocity model 
was supplemented with valuable information within the upper 80 m resulting in a surprisingly low P- and S – wave ve-
locities. Such low velocities, however, seem to agree with a recently drilled cored permafrost well at CO2 Lab, and the 
presence of partially soft soil lenses within the upper 65 m. This also explains the observation of strongly attenuated 
S- wave energy at the near surface geophone opposed to the deeper geophones in the well DH3. Optimum P- wave 
observations can thus only be provided by downhole geophone installations placed below the unconsolidated soft 
sediments in the permafrost zone. The new insight on the shallow velocity structure will further improve the location 
accuracy of the injection-related microseimicity and allows combining surface geophone observation with downhole 
geophone observations more consistently without the need for heavily biased static corrections.

Seismics monitoring


From the results of this monitoring campaign a de-
tailed study of the acoustic challenges around the 
seismic lines with the intrusions and especially the 
potential for imaging a CO2 plume in the project 

area was undertaken as a Master project by Mik-
kelsen (2009).  A velocity model has since been con-
structed by Norsar using results from this investiga-
tion, advancing on a first VSP analysis by READ (see 
Braathen et al. 2012).

Photo b

y: Bælum