ph.d student at lmv/chalmers
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Ph.D student at LMV/Chalmers
Topic : Gravimetry (AG, SG) Student : Per-Anders OlssonSupervisor : Hans-Georg Scherneck
(Jonas Ågren)Where? : LMV/ChalmersFinanced by: LMVWhen? : 2007-09-01 2013-12-31??
First project – Baltic Sea
Paper to Jena 2008-09-01
Why Baltic Sea?
• Large amplitude
• Not periodic
• Not handled (FG5)
• Data ”avaliable”
• Unique conditions
• Short and long term effects
Theoretical approach
1. Farrell, W.E., 1972. Deformation of the Earth by Surface Loads, Reviews of Geophysics and Space Physics, 10, 761-797.
2. Jentzsch, G., 1997. Earth Tides and Ocean Tidal Loading. in Tidal Phenomena, pp. 145-172, eds. Wilhelm, H., Zürn, W. & Wenzel, H.-G. Springer-Verlag, Berlin Heidelberg.
seasurface
g dAHGg )()(
Spherical, elastic earth
Greens function for gravity
Convolution of Greens function and sea surface
Newtonian effect at height
Load love numbers from• G-B Earth Model1• PREM reference earth model2
Some examples
…the purpose of the following is not to present any results (everything is
still preliminary), I just want to give You an idea of what
I am working with and hopefully get some response to that.
Please, be aware…
Stations and grid
10 degree sea surface Baltic sea surface
One meter water (1)
Station Newton Loading Total Newton Loading Total
Arjeplog 1.79 3.97 5.76 0.29 0.69 0.98
Kiruna 1.86 4.11 5.97 0.24 0.50 0.74
Kramfors 2.40 3.99 6.39 1.59 2.38 3.97
Kungsholmsfort 7.13 4.89 12.02 6.61 3.70 10.31
Mårtsbo 1.37 3.88 5.25 0.69 2.55 3.24
Onsala 1.82 5.11 6.93 0.39 1.09 1.48
Skellefteå 1.64 3.89 5.53 0.67 1.98 2.66
Smögen 5.47 5.34 10.81 0.37 0.93 1.29
Visby 1.56 5.04 6.59 1.11 4.16 5.27
Östersund 1.71 3.78 5.48 0.38 0.99 1.37
Ratan 1.72 4.24 5.96 0.87 2.59 3.46
Lycksele 1.48 3.42 4.90 0.42 1.25 1.67
LMV 1.42 3.98 5.40 0.65 2.49 3.14
Metsähovi 0.92 2.95 3.87 0.68 2.53 3.22
10 degree sea surface Baltic sea surface
All numbers in gal
One meter water (2)
Distribution of the loading effect
Data from SMHI (1)
Stn_name
Sealevel [cm]
2008-03-06
2008-03-27
Kalix 78 -60
Furuogrund 80 -50
Ratan 75 -42
Spikarna 70 -20
Forsmark 60 -12
Stockholm 65 10
Landsort_Norra 57 20
Marviken 45 12
Oskarshamn 30 30
Kungsholmsfort -10 40
Simrishamn -30 40
Skanor -60 45
Klagshamn -55 40
Barseback 0 30
Ringhals 30 15
Goteborg 35 5
Smogen 35 0
Kungsvik 35 0
Data from SMHI (2)
2008-03-06 2008-03-27
Data from SMHI (3)
Stationg [gal]
2008-03-06 2008-03-27
Arjeplog 0.73 -0.25
Kiruna 0.77 -0.20
Kramfors 2.65 -0.82
Kungsholmsfort -0.34 3.70
Mårtsbo 1.86 -0.19
Onsala 0.91 0.54
Skellefteå 1.92 -0.96
Smögen 2.29 0.25
Visby 2.01 0.95
Östersund 0.89 -0.19
Ratan 2.43 -1.10
Lycksele 1.13 -0.40
LMV 1.78 -0.19
Metsähovi 1.70 -0.29
Sensitivity of location (1)
text
H/10 < Thetacritical < H*10
One meter water, 10 degree sea surface
StationDistance from
coast [m]Height (RH2000)
[m]Direct attraction
[gal]
Direct attractionH = 0
[gal]
Diff[gal]
Arjeplog 156000 450 1.79 1.76 0.03
Kiruna 154000 466 1.86 1.83 0.03
Kramfors 1120 120 2.40 1.39 1.01
Kungsholmsfort
10 2 7.13 1.295.84
Mårtsbo 7380 44 1.37 1.32 0.05
Onsala 170 6 1.82 1.54 0.28
Skellefteå 1360 55 1.64 1.46 0.18
Smögen 20 6 5.47 1.65 3.82
Visby 2770 46 1.56 1.34 0.22
Östersund 150000 453 1.71 1.67 0.04
Ratan 2200 53 1.72 1.45 0.27
Lycksele 113400 245 1.48 1.46 0.02
LMV 2720 14 1.42 1.40 0.02
Metsähovi 16400 56 0.92 0.88 0.04
Sensitivity of location (2)
Long term sea level change
Station Delta_g [gal/year]
Arjeplog -0.0087
Kramfors -0.0351
Kungsholmsfort -0.0137
Mårtsbo -0.0217
Onsala -0.0107
Skellefteå -0.0250
Smögen -0.0267
Visby -0.0164
Östersund -0.0110
Ratan -0.0318
Lycksele -0.0142
LMV -0.0208
Metsähovi -0.0148
Storm in the Baltic Sea 1872
Station Newton Loading Total
Gedser 55.3332 4.8397 60.17
Kungsholmsfort 8.3527 3.1339 11.49
Onsala -0.4211 -1.1027 -1.52
Smogen -3.4792 -1.5830 -5.06
Visby 0.0919 0.4216 0.51
Sea level in Danish foot (0.3 m)
All numbers in gal
Conclusions...
To come…
… Baltic loading
… Groundwater
… Atmospheric loading
… GIA
… SG/AG
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