Jökull - 01.01.2010, Page 14

Geirsson et al.
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Figure 6
Figure 6. Time series of the motion of site THEY, south of Eyjafjallajökull covering the 2009-2010 intrusive
and eruptive episodes. The time series are plotted relative to REYK (hence the overall eastward drift), and are
from IMO’s low latency automatic data processing using Bernese V 5.0 with predicted orbits from Center of
Orbit Determination in Europe (CODE). The gray areas note periods of intrusion into the volcano, and the red
lines indicate the times of the start of the flank eruption (F), and summit eruption (S). The gray period "1" marks
the May to August 2009 intrusion, period "2" starts at the onset of the inflation in December 2009 and ends at
period "3", when the station started moving towards west because material was being intruded east of the station
(Sigmundsson et al., 2010). – Tímaröð hreyfinga GPS stöðvarinnar THEY miðað við REYK (Mynd 1). Stöðin
er sunnan við Eyjafjallajökul. Skyggð svæði 1 til 3 tákna tímabil innskota og rauðu línurnar upphaf eldgosa á
Fimmvörðuhálsi (F) og í toppgígnum (S). Á tímabili 1 var aukin skjálftavirkni og aflögun frá maí til ágúst 2009.
Við byrjun tímabils 2 hélt innskotavirknin áfram, og á tímabili 3 færist stöðin ekki út frá miðjum Eyjafjallajökli,
heldur til vesturs vegna innskots austan við stöðina, undir suð-austanverðum Eyjafjallajökli (Sigmundsson et
al., 2010).
nunatak, a special monument was designed by IMO
technical staff for the site in 2006, installed on the
same foundation as the original monument. The mon-
ument consists of a 2 m high metal pier anchored to
the bedrock. The pier receives heat from a geothermal
well close to the monument, and is covered by a high-
gloss black plastic tube to prevent ice from collecting
on the monument. Despite these preventive actions,
there still are periods of intense icing that cause ap-
parent changes in the site position (Figure 7).
14 JÖKULL No. 60