place in the same area on 5
December in 1968 (Tryggvason, 1973; Erlendsson and Einarsson, 1996; Halldórsson,
2004). A quite large event also occurred on the RP on 10 June 1933. Its best known
location is near to Fagradalsfjall, at 63.9°N and 22.2°W, and it was probably of magnitude
M 5.5 (Tryggvason, 1973; Halldórsson, 2004).
8
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ig
ure
1
.3
.
A
m
a
p
s
h
o
w
in
g
e
p
ice
n
tr
e
lo
/media/vedurstofan/utgafa/skyrslur/2010/2010_003rs.pdf
NKG2016LU_lev (Lantmäteriet, n.d.(b)). UK: Based on CGPS data, modified from figure 1b p. 16
in Bradley et al. (2009). Iceland: Based on 1993 - 2004 GPS data, modified from figure 5.18, p. 101
in Björnsson et al. (2018).
15
are ongoing isostatic changes in Iceland. The vertical motion of the Icelandic crust is very region
specific with the fastest uplift in the Southeast close to the largest
/media/vedurstofan-utgafa-2020/VI_2020_005.pdf
performance of the
model.
REFERENCES
Førland, E. J., Allerup P., Dahlström B., Elomaa E., Jónsson T., Madsen H.,
Perälä J., Rissanen P., Vedin H. and Vejen F. 1996. Manual for operational cor-
rection of Nordic precipitation data. DNMI Report No. 24/96 Klima, 66 pp.
Benoit, R., Pellerin P., Kouwen N., Ritchie H., Donaldson N., Joe P. and Soulis
E. D. 2000. Toward the use of coupled atmospheric
/media/ces/Paper-Olafur-Rognvaldsson_92.pdf
seismicity near to the eruption site in the morning of the 21st.
On the vertical section viewed from the south two velocity models are shown, the SIL-model (black lines) used for the automatic and daily manual location processes, and the improved South-Iceland model (P23, green lines) used in the relocation process. Thin lines show S-wave velocity and thick lines show P-wave velocity.
Eruption site
/about-imo/news/nr/1859
is characteristic for a surface wave. As no body waves are seen prior to the low frequency onset, this event clearly differs from a normal tectonic earthquake which usually starts with clear onsets of P- and S-waves prior to the surface waves.
Figure 2
Interpretation
The preliminary interpretation of this signal is that the low frequency waves in the beginning reflect a slow rupture process
/earthquakes-and-volcanism/articles/nr/2921
of
earthquakes.
Reference:
[1] Korja, A. and Kosonen, E. M. (eds.) 2015. Seismotectonic framework and seismic source area models in Fennoscandia,
Northern Europe. Univ. Helsinki, Instit. Seismology, Report S-63, 284 p.
http://www.seismo.helsinki.fi/pdf/Seismotectonic_S63_Korja_Kosonen.pdf
[2] Nørbech, T., Engsager, K., Jivall, L., Knudsen, O., Koivula, H., Lidberg, M., Ollikainen, M. & Weber, M., 2008
/media/norsem/norsem_korja.pdf