Nordic Geodetic Commision, WG for Geodynamics, Annual Meeting 2005, Masala /Finland, May 3-4

Fennoscandian Uplift Observed with Fennoscandian Uplift Observed with Absolute Gravity Measurements in the Absolute Gravity Measurements in the

Period 1991 to 2003Period 1991 to 2003 H. Wilmes 1), R. Falk 1), F. Klopping 2), E. Roland 3),

A. Lothhammer 1), A. Reinhold 1), B. Richter 1), H.-P. Plag 3), J. Mäkinen 4)

1) Bundesamt für Kartographie und Geodäsie (BKG), Germany 2) National Oceanographic and Atmospheric Administration (NOAA), U.S.A.

3) Norwegian Mapping Authorities (NMA), Norway 4) Finnish Geodetic Institute (FGI), Finland

Nordic Geodetic Commision, WG for Geodynamics, Annual Meeting 2005, Masala /Finland, May 3-4

Project with participation of:

• NGS / NOAA (USA)• BKG (Germany)• NMA / Statens Kartverk (Norway)• FGI (Finland)• Lantmäteriet (Sweden)

K oszalin

Pasewalk

R ostockF len sbu rg

Vasa

M etsahovi

Trom soe

K irun a

F u ru oegrun d

M artsbo

O nsala

H oen efoss

Tron dh eim

Trysil

S tavan ger

Vagstran da

Absolute Gravity Determination in the Scandinavian Land-Uplift Zone 1991 - 2003

Nordic Geodetic Commision, WG for Geodynamics, Annual Meeting 2005, Masala /Finland, May 3-4

Absolute gravity measurements in Martsbo/Sweden

Mårtsbo (S), observed gravity changes

gmean@125 cm = 981 923 082,4 µGal (gradientmean = 287,5 µGal/m)

-15

-12

-9

-6

-3

0

3

6

9

12

15

1991 1993 1995 1997 1999 2001 2003

[µG

al]

JILAg-5

FG5-111

FG5-101

FG5-301

Martsbo(Sweden)

-1,29 µGal / year± 0,3 µGal / year

Nordic Geodetic Commision, WG for Geodynamics, Annual Meeting 2005, Masala /Finland, May 3-4

Sta

tio

n

Ob

se

rva

-ti

on

s

Pe

rio

d

ye

ars

up

lift

rate

in

µ

Ga

l/ye

ar

up

lift

rate

in

µ

Ga

l/ye

ar

up

lift

rate

in

µ

Ga

l/ye

ar

Stavanger AA 4 91-03 11,9 -0,6 +/- 0,18 -0,5 +/- 0,51 -0,4 +/- 0,44Hoenefoss AB 3 93-03 9,8 -1,0 +/- 0,23 -1,0 +/- 0,54 -1,0 +/- 0,54

Hoenefoss AC * 2 95-03 7,7 -0,6 -0,6 -0,6Trysil AC 6 93-03 9,9 -1,2 +/- 0,20 -1,1 +/- 0,30 -1,1 +/- 0,30

Trysil AC with AB 9 93-03 9,9 -1,2 +/- 0,18 -1,2 +/- 0,28 -1,2 +/- 0,28Trondheim AA 3 95-03 7,8 -2,5 +/- 0,30 -2,5 +/- 0,76 -2,5 +/- 0,76Tromsoe AA 5 92-03 11,3 -0,3 +/- 0,51 -0,4 +/- 0,37 -0,4 +/- 0,32

Kiruna * 2 95-03 7,8 -1,1 -1,1 -1,1Furuoegrund AA 5 92-03 11,4 -2,0 +/- 0,18 -2,0 +/- 0,44 -1,9 +/- 0,38

Mårtsbo AA 4 93-03 10,3 -1,3 +/- 0,27 -1,3 +/- 0,54 -1,3 +/- 0,46Onsala AS 6 93-03 10,3 -0,9 +/- 0,20 -0,9 +/- 0,33 -0,8 +/- 0,29

Onsala AS with AN 9 93-03 10,3 -0,9 +/- 0,18 -0,9 +/- 0,30 -0,8 +/- 0,26

FG5 and JILAg-5 propagation of à priori errors

1 σ

err

or

es

tim

ate

—

—

FG5 only,simple line fit

FG5 only,propagation of à priori errors

1 σ

err

or

es

tim

ate

—

1 σ

err

or

es

tim

ate

—

—

—

Observed Mean Gravity Rates

* only 2 observations

Nordic Geodetic Commision, WG for Geodynamics, Annual Meeting 2005, Masala /Finland, May 3-4

GPS at Martsbo

GPS-time serieEPN (EUREF Permanent Network)

Nordic Geodetic Commision, WG for Geodynamics, Annual Meeting 2005, Masala /Finland, May 3-4

Outline

K oszalin

Pasewalk

R ostockF len sburg

Vasa

M etsahovi

Trom soe

K irun a

F uru oegrun d

M artsbo

O nsala

H oen efoss

Tron dheim

Trysil

S tavan ger

Vagstran da

10 mm / year(Kaniuth/Vetter 2004)

-2 µGal / year

G PS up lift ra tes

(BIFROST 2001)

G PS up lift ra tes 10 mm / year

G ra vity c ha nges

Compilation of gravity changes and GPS uplift rates

Nordic Geodetic Commision, WG for Geodynamics, Annual Meeting 2005, Masala /Finland, May 3-4

Conclusions

• More than 10 years of absolute gravity observations clearly reveal long term gravity changes related to post glacial uplift

• Combination of data from different groups and instruments make instrumnet monitoring and comparison an importand precondition

• Seasonal gravity variations are not accesible with present data and have been assigned for in the error estimation

• The local gravity field at the stations need to be checked.(e.g. building activities in Trondheim cover the gravity signal)

• More complete environmental data improve the description of seasonal gravity variations

Nordic Geodetic Commision, WG for Geodynamics, Annual Meeting 2005, Masala /Finland, May 3-4

European Combined Geodetic Network ECGN- Status Report -

Website of ECGN Project

http://www.bkg.bund.de/ecgn

ECGN Website Guidelines and Forms with links to guidelines and forms for the different observation techniques

Johannes Ihde, Trevor Baker, Carine Bruyninx, Olivier Francis, Martine Amalvict, Ambrus Kenyeres, Jaakko Makinen, Steve Shipman, Jaroslav Simek, Herbert Wilmes

Nordic Geodetic Commision, WG for Geodynamics, Annual Meeting 2005, Masala /Finland, May 3-4

European Combined Geodetic Network ECGN- Status Report -

• Maintenance of long time stability of the terrestrial reference system with an accuracy 10-9 for Europe especially in the height component

• In-situ combination of geometric positioning (GPS) with physical heights and other Earth gravity parameters in 1 cm-accuracy level

• Modelling of influences of time depended parameters of the solid Earth of the Earth gravity field, the atmosphere, the oceans, the hydrosphere for different applications of positioning

Integrated European Reference System for Spatial Reference and Gravity

Nordic Geodetic Commision, WG for Geodynamics, Annual Meeting 2005, Masala /Finland, May 3-4

European Combined Geodetic Network ECGN- Status Report -

This call concerns the elaboration of the observation network of ECGN stations with the standard observation techniques:

     GNSS (GPS/GLONASS, GALILEO) – permanent

      Gravity (super conducting gravimeter – permanent

and/or absolut gravimeter) or repeated

      Levelling connections to UELN/EVRS – repeated

      Tide gauges – permanent

      Meteorological parameters – permanent.

Nordic Geodetic Commision, WG for Geodynamics, Annual Meeting 2005, Masala /Finland, May 3-4

European Combined Geodetic Network ECGN- Status Report -

ECGN status 1st call proposals

•20 countries•72 stations with

GPS (EPN)absolut gravity levelling to EVRS 6 super conducting gravimeters 15 tide gauges

Nordic Geodetic Commision, WG for Geodynamics, Annual Meeting 2005, Masala /Finland, May 3-4

European Combined Geodetic Network ECGN- Status Report -

Meta Data – in general the ECGN project based on existing

data– only the information about the data i.e. meta

data should be collect– therefore in the meta data form the availability

of the data and the access to the data should be described

– the local ties are also a part of the form– ECGN Meta Data Form (see ECGN Website –

PDF/TXT File)

Present Status, ECGN Meta Data Base

Nordic Geodetic Commision, WG for Geodynamics, Annual Meeting 2005, Masala /Finland, May 3-4

European Combined Geodetic Network ECGN- Status Report -

The second ECGN call is still a matter of further discussions. It will include the status of the project (stations, data availability, meta database, data policy). In a second call it could be asked for:

• Methodical investigations for the combination of spatial observation data with gravity field related data

• AG/SG combination• AG/SG array for GOCE validation• Combination of space techniques (GPS/GLONASS,

GALILEO, VLBI, SLR)• Single station analysis of different observation techniques• Analysis centers for the combination of time series of all

ECGN stations• Establishment of co-operations to solve the above

mentioned questions

Methodology and Analysis (2nd Call postponed)

Nordic Geodetic Commision, WG for Geodynamics, Annual Meeting 2005, Masala /Finland, May 3-4

Construction of an integrated geodetic network in Germany

-permanent GPS

-Levelling

-Absolute gravity measurements and SCG stations