Magnetic Repeat Station Measurements in Europe

Transcription

1 Magnetic Repeat Station Measurements in Europe MagNetE-Report / Update (Report: G. Duma, gerald.duma@zamg.ac.at) Overview on survey activities in the countries, no measurement results are given TABLE OF CONTENT Reports by country... 3 Albania... 3 Austria... 3 Belarus... 4 Bulgaria... 5 Croatia... 5 Czech Republic... 6 Estonia... 6 Finland... 7 France... 8 Germany... 8 Hungary... 9 Italy, Sardinia, Corsica Ireland Latvia Lithuania Macedonia Poland Romania Serbia and Montenegro Slovakia Spain... 17

2 2 Switzerland United Kingdom Ukraine MAP Magnetic Repeat Stations Points of Contact Albania Austria Belarus Bulgaria Croatia Czech Republic Estonia Finland France Germany Hungary Italy, Sardinia, Corsica Ireland Latvia Lithuania Macedonia Poland Romania Serbia and Montenegro Slovakia Spain Switzerland United Kingdom Ukraine... 25

3 3 Country in alphabetic order Albania Reports by country Reported by G. Dominici, A. De Santis, A. Meloni, M. Miconi, Italy Comments Albania See Italy Updates of information - Albania Austria Reported by G. Duma, B. Leichter, J. Berger Comments Austria The 14 repeat stations in Austria are measured every year. Mean station distance is 100 km. The measurement points were stabilized by pillars, their coordinates were determined by triangulation within the Austrian geodetic network. Instruments: DI Fluxgate (Bartington), Gyro SOKKIA GP1-2, Proton Magnetometer ELSEC 820 (Littlemore). Survey period: May September, partial surveys of a few days each. At each repeat station control measurements are performed first to detect any magnetic active waste deposited recently: F vertical control profile above the pillar, F horizontal control profiles, 5 m around the pillar In 2005, the measurements were performed in the evening and next morning, following the recommendations to measure during magnetically quiet hours. The years before the measurements were carried out during daytime. The results reveal a higher data accuracy, indeed. In 2006 we want to find out, if just one measurement sequence in the evening will be sufficient. F is measured at the pillar point at the begin and at the end of the DI measurements. We run the proton magnetometer (10 values) during the whole DI prozedure, in some 15 m distance from the measurement point, in order to have the F-

4 4 values available for each DI reading. Before and after each partial survey, absolute measurements are done at the magnetic observatory Wien-Cobenzl, respectively, to control instrument performance. As to the determination of true North, the gyro accuracy turned out to be some 30 on average. Secular station measurements are reduced to the middle (1 st July) of the current year, respectively. Use of magnetic repeat measurement data: Annual update of the geomagnetic charts of Austria, information service, correlation of secular variation and earthquake activity in Austria Updates of information Austria REPEAT STATION MEASUREMENTS IN AUSTRIA 2005 GEOMAGNETIC VARIATIONS AND EARTHQUAKE ACTIVITY Questionnaires 2007: MagNetE Repeat Station Survey description-at Repeat station measurements in Austria Geomagnetic data and surveys of Austria-Hungary in the 19th century RS-ENTER software for conversion of RS data Update of the MagNetE-Report Belarus Reported by E.Welker, Poland Comments Belarus Updates of information Belarus

5 5 Bulgaria Reported by I. Cholakov, B. Srebrov Comments Bulgaria Each point is measured three days by two observers in the time when the difference in the diurnal variations between Panagjurishte observatory and the point is the least. The following geomagnetic elements are measured: D by magnetic theodolite ; H by three QHM and F by proton magnetometer. Measurements 2007 by DI theodolite. Updates of information Bulgaria REPEAT STATION NETWORK IN BULGARIA Questionnaires 2007: MagNetE Repeat Station Survey description-bg Croatia Reported by Mario Brkić, D. Šugar, M. Pavasovic, M. Rezo, E. Vujic, E. Begovic Comments Croatia Our first survey has been in the year of 2004, when eight repeat stations were setup. There was no repeat stations survey in Croatia in the year of The measurements are to be done at only one (POKUpsko) repeat station this year. However, the survey of whole network, along with setup and survey of two new repeat stations, are planned in the year of Also we welcome the proposed informal meeting (at IAGA-Workshop 2006). Our contribution to the GFZ Scientific Technical Report will be reduced 2004 survey data, not yet published.

6 6 Updates of information Croatia THE 2004 GEOMAGNETIC REPEAT STATION SURVEY Questionnaires 2007: MagNetE Repeat Station Survey description-hr Croatian Geomagnetic Surveys Czech Republic Reported by P. Hejda, J. Horáček, T. Bayer Comments Czech Republic On the territory of Czech Republic we have 7 repeat stations and the measurement was made in the years 2001, 2003 and Now we are prepared to start measurement in the beginning of May to finish it till the IAGA Workshop in Belsk. On every station the measurement is repeated 8 times and is reduced according three registrations. Azimuth is measured by determining the Sun's positions. For measurement of gradient on each station we use gradiometer GEM System, model GSM-19G. Updates of information Czech Republic CZECH NATIONAL REPORT Questionnaires 2007: MagNetE Repeat Station Survey description-cz Geomagnetic field measurements at the Czech Republic territory for Some remarks to the derivation of hourly mean values with incomplete data Estonia Reported by K. Pajunpää, J. Kultima, T. Raita Finland

7 7 Comments Estonia See Finland Updates of information Estonia MagNetE workshop Bucharest 2007 (see Finland): ABOUT PROBLEMS OF GETTING SECULAR DATA Finland Reported by K. Pajunpää, J. Kultima, T. Raita, H. Nevanlinna, L.Häkkinen Comments Finland Repeat stations in Finland and in Estonia with three-letter codes are all IMAGE stations with permanent magnetic recording. The motivation for the repeat station measurements is mainly scientific. We try to keep a reasonable network (with km between the sites) to support the global effort for the main field modelling. Another use is updating the data base for the magnetic maps of Finland and Estonia. Our work is closely related to the maintenance of the IMAGE magnetometer network. The service of a station usually includes an absolute observation. The measurements are done by Nurmijärvi (Pajunpää) and Sodankylä (Kultima) observatories.

8 8 Updates of information Finland ABOUT PROBLEMS OF GETTING SECULAR DATA Questionnaires 2007: MagNetE Repeat Station Survey description-fi Past and present of repeat station measurements in Finland Historical geomagnetic observations - Data sources for secular variations and space weather studies France Reporting persons: Stuart GILDER(gilder@ipgp.jussieu.fr), François TRUONG(ftruong@ipgp.jussieu.fr), Kader TELALI, E. ipgp.jussieu.fr), A. ipgp.jussieu.fr) Comments France Updates of information France FRENCH CONTRIBUTION Questionnaires 2007: MagNetE Repeat Station Survey description-fr Germany Reported by M. Korte, M. Mandea, N. Olsen, M. Fredow, Vincent Lesur Comments Germany The concept is to measure all stations within one year every two years. A complete survey of all stations was last carried out in The whole network will be surveyed in The stations will be surveyed in several individual trips to the different parts

9 9 of the country between April and October In my opinion, the station density of repeat stations is too scarce to be useful for crustal field studies (unless combined with aermomagnetic data), so the main purpose would be secular variation studies. To monitor secular variation in detail, short time intervals of occupation are desirable, and 2 years seems to be a reasonable compromise with what is feasible. However, in a region with a comparatively high density of geomagnetic observatories, a very high accuracy of repeat station results is important that we can gain additional information from these surveys. This particularly includes minimising the influence of external and induced variations of the geomagnetic field. Updates of information - Germany OBSERVATORY DATA REPEAT STATION MEASUREMENTS IN GERMANY 2006 REPEAT STATION CRUSTAL BIASES AND ACCURACY DETERMINED BY REGIONAL FIELD MODELS Questionnaires 2007: MagNetE Repeat Station Survey description-de The German Repeat Station Survey 2008 Secular variation in Germany from repeat station data and a recent global field model The European geomagnetic secular variation and acceleration over the last four decades Hungary Reported by A. Csontos, P. Kovács, B.Heilig Comments Hungary The average distance between next stations (2006) is not more than 100 km. It is necessary we will leave over some stations if the weather is very rainy in autumn. The instrumentation will be basically the same like in the past campaign. (ZEISS 020A D&I theodolite and GSM-19 magnetometer) The scientific plans of this campaign are: - The most basic purpose is to determinate secular variation of the stations. - Due to non anomalous network the measured values give possibility to follow the change of space distribution of the geomagnetic normal field our country.

10 10 - We are planning to test an "on station" magnetometer on one or two far station(s) in order to get better accuracy of data. The magnetometer will be a suspended didd system. - If it is possible (I am not sure) our institute will carry out magnetotelluric measurements simultaneously with the didd system at the same station. The reason of this measurement is separating the sources of the external influences of the geomagnetic field and knowing some details about the behaviour of the difference of magnetic fields between the station and the observatory. - We started with mapping the geomagnetic normal field in Middle-Europe. We use spherical cap model and we are planning to integrate satellite and repeat stations data. Updates of information - Hungary HUNGARIAN REPEAT STATION SURVEY 2006 Latest results of the Hungarian repeat station surveys Italy, Sardinia, Corsica Reported by G. Dominici, A. De Santis, A. Meloni, M. Miconi, M. Pierozzi, M. Sperti Comments Italy Report on the Magnetic Repeat Station Survey of 2005 in Italy G. Dominici, A. De Santis, A. Meloni and M. Miconi Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy In Italy the magnetic measurements are normally made over the repeat stations network every 5 year, as suggested by IAGA (see Newitt et al.,1996). Last magnetic filed network results were reported in Bollettino di Geodesia e Scienze Affini, Anno LX, 4, After the national repeat stations campaign carried out in Italy around 2000, the new survey for 2005 has begun in September In this occasion magnetic measurements were also made in Albania (together with Academy of Science of Albania and Tirana University) and then in Italy. The complete survey was finally completed on November, The complete set of repeat station locations including the Albanian part and the associated period of measurements is given in figure 1. Including the Albanian stations the 2005 survey finally comprised total number of 133 repeat stations, including

11 11 also the two Italian Observatories L Aquila and Castello Tesino. In order to complete the magnetic field knowledge in the Tyrrhenian area 3 magnetic repeat stations were also made in Corsica with an agreement with the IPGP Paris, and some minor islands in Italy. The density of the Network is larger than typical European networks. However the number of stations and their distribution were also finalized to other studies, related for example to the geodynamical evolution of this part of the Mediterranean. Repeat station measurements were undertaken with standard instrumentation, a fluxgate-theodolite for measurements of D,I, various types of proton precession magnetometers for F, and a gyroscopic theodolite for azimuths. Measurements at each repeat station were made as 10 sets of measurements: five in the morning at about Local Time (LT) am., and five in the afternoon at about LT pm. Each value of some element E must be reduced to the epoch , following two steps: Es(02 UT) = Evar(02 UT) + [Es(t) Evar(t)] (1) Es(2005.0) = Eobs(2005.0) + [Es(02 UT) Eobs(02 UT)] (2) Where: Es(02 UT)= Value of E at station s reduced at time 02 UT of day of measure Evar(02 UT)= Value of E at station s at time 02 UT of day of measure Es(t) = Value of element E observed at station s at time t Evar(t)= Value of element E at station s at time t Eobs(t) = Value of element E measured at the Observatory at the same time t Es(2005.0)= Value of element at station s reduced to epoch Eobs(2005.0)= Mean value of element at the Observatory for epoch For the step (1) the diurnal variation correction has been calculated using digital data from L Aquila or Castello Tesino Observatory, or portable variometer when the station is far from the two Observatories. The variometer consisted of a three-axial fluxgate with the sensor set in D,H and Z orientation; the setting of the instrument in the field was such that initially the recording of the Y-sensor reads 0. The Y and X sensor thus record D (in nt) and H respectively. All variometers were previously tested for a high-quality baseline stability. L Aquila magnetic Observatory is used as reference for secular variation monitoring. Currently the final average value of L Aquila Observatory Eobs(2005.0) magnetic elements is still under computation and in this report the values of the

12 12 magnetic elements are reported as reduced at the quiet night time Es(02 UT), to make such our data more practical for modellers working on temporally continuous models. Values of all magnetic elements and geographical information are reported according to IAGA format in table 1 Following the suggestions given by the Group for the European Repeat Station Surveys to repeat the measurements every 2 years, although a complete repeat Survey in Italy will be made in 2010, we plan to repeat a sub ensemble (say repeat stations) of the entire Network at 2 year periodicity. Acknowledgements We wish to thank Dr. B.Duka and Dr. S. Bushati for their assistance in the survey of Albania. References A.Coticchia,A De Santis, A. Di Ponzio, G.Dominici, A Meloni, M.Pierozzi, M.Sperti(2001), Italian magnetic network and geomagnetic field maps of Italy at year , Boll.Geod. Sci.Affini, 4, L.R. Newitt, C.E. Barton, J. Bitterly (1996), Guide for magnetic repeat station surveys, IAGA Working Group. Map of all station positions available. Updates of information Italy, Sardinia, Corsica ITALIAN MAGNETIC NETWORK AND GEOMAGNETIC FIELD MAPS OF ITALY AT YEAR 2005 Geomagnetic Survey of Italy at Ireland Reported by E. Moran

13 13 Comments Ireland Data of 2005 not processed yet, but will be made available as soon as possible. Staff shortage will result in a significant delay in our survey plans. We will be conducting no surveying in 2006 but expect to complete at least 9 stations in Updates of information - Ireland Latvia Contact Persons (see below): L. Sulakova, A. Zjatkovs Comments Latvia Updates of information - Latvia Lithuania Reported by E.Welker, Poland Comments Lithuania Stations reported by E. Welker

14 14 Updates of information - Lithuania Macedonia Reported by M. Delipetrev, S. Panovska, T. Delipetrov, B. Doneva, B. Delipetrov Comments Macedonia In 2002, we measured only three repeat stations (Plackovica, Ponikva and Galicica). In 2003 was established this network of repeat stations in the Republic of Macedonia after the disintegration of Yugoslavia. These 15 repeat stations were measured in 2003 and 2004, we planned measurements in No measurements were done in We haven't a Geomagnetic Observatory but we plan to build it in Plackovica. Updates of information - Macedonia GEOMAGNETIC MEASUREMENTS Questionnaires 2007: MagNetE Repeat Station Survey description-mc Poland Reported by E. Welker, A.Sas-Uhrynowski Comments Poland Station map available

15 15 Updates of information - Poland MAGNETIC FIELD CHANGES IN THE YEARS 1980 Questionnaires 2007: MagNetE Repeat Station Survey description-pl Report about the measurements at the repeat stations Secular variations of the geomagnetic field in Europe, Romania Reported by C. Demetrescu, L. Besutiu, L. Atanasiu, L. Zlăgnean, V. Dobrica, M. Ene, A. Soare, G. Cucu, I. Vaduva Comments Romania The Romanian repeat stations were reoccupied in 2004, we planned measurements in 2006, and intend to do measurements in 2007 too. No measurements were done in 2005 (interruption of recording at Surlari observatory, due to equipment failure for several months). Updates of information - Romania AN ANALYSIS OF LONG LONG-TERM VARIATIONS NEAR SURFACE LARGE SCALE GEOMAGNETIC MAPPING THE 2006 GEOMAGNETIC REPEAT STATION SURVEY The geomagnetic repeat station survey Romania On the high frequency ingredients of the secular variation

16 16 Serbia and Montenegro Reported by N. Smiljanic, D. Popeskov, S. Mihajlovic, D. Zivkovic Comments Serbia and Montenegro Report will follow Updates of information - Serbia and Montenegro GEOMAGNETIC FIELD MEASURMENT AT REPEAT STATIONS Slovakia Reported by F. Valach, M. Vaczyova,, P. Dolinsky, M.Hvozdara Comments Slovakia We intend to perform the measurements every two years. Updates of information - Slovakia SLOVAK REPEAT STATIONS Magnetic ground and repeat station surveys in Slovakia for the years

17 17 Spain Reported by I. Socias, V. Marin, P. Covisa, C. Domingo, J.Fernandez Comments Spain Data of the repeat stations observed during 2005 are reduced to using San Pablo observatory for reduction. As you ca see is more or less the north half of Spain, and the ones near Ebro observatory will be also reduced with this one, to compare results. For 2006 we will observe the other half, including the Balearic islands, and it is also thought to introduce variometers from this survey on. Updates of information - Spain SPANISH MAGNETIC REPEAT STATION SURVEY ISOPORIC MODELLING OF THE GEOMAGNETIC FIELD COMPONENTS AT THE EPOCH 2005 Questionnaires 2007: MagNetE Repeat Station Survey description-es Spanish repeat stations surveys (2007 and 2008) Switzerland Report by P. A. Schnegg Comments Switzerland

18 18 Updates of information - Switzerland Questionnaires 2007: MagNetE Repeat Station Survey description-ch United Kingdom Reported by S. Macmillan, T. Shanahan, S. Reay Comments UK The geomagnetic field was measured at 12 of the 51 stations in the UK during Their locations are shown on the map (available) and the data, reduced to quiet levels, are available at Use of data: The data are used to map the geomagnetic field and its secular variation over the UK. An application is the provision of magnetic north information for maps produced by the national mapping agency, the Ordnance Survey. Updates of information - UK UK REPEAT STATION PROGRAMME RECENT CHANGES AT WORLD DATA CENTRE FOR GEOMAGNETISM (EDINBURGH) Questionnaires 2007: MagNetE Repeat Station Survey description-uk UK Repeat Station Report Status of Edinburgh WDC Global Survey Data Ukraine Reported by V.Maksymchuk, Yu.Gorodysky, V.Kusnetsova, V. Tregubenko, Y. Horodyskyy, M. Orlyuk, E. Nakalov, I. Chobotok, V. Myasoedov

19 19 Comments Ukraine 1.Because of financial problems we have no opportunity to fulfill repeat stations measurements, covering all the Ukraine. At least we can do this only 1 time in 5 years. 2. We plan to measure every 2 years in Carpathians network (8 10 stations). 3. In we are planning to measure in 44 stations (the whole Ukrainian network). But it would depend on a governments founding. 4. We consider 2-years interval of measurements is optimal. 5. The last cycle of geomagnetic observations in Ukraine was fulfilled in 2004 in 8 repeat stations. All of these repeat stations are located in the Carpathians region, in the Western Ukraine. They were based in The measurements of D and I were done by the means of fluxgate magnetometers LEMI-203. The measurements of F by the means of a proton magnetometer MB-01. X, Y, Z components were calculated. The measure reference object s azimuth was defined by Sun. Reducing to 2004,5 was done on the base of Lviv magnetic observatory. Updates of information - Ukraine REPEAT STATIONS MEASUREMENTS IN UKRAINE Ukraine magnetic repeat stations survey ( ) MAP Magnetic Repeat Stations The map shows only those stations, which were/will be measured in the period MagNetE_Stations_2005_2007.jpg

20 20 Points of Contact Albania Contact Person(s) Institution Guido Dominici Angelo De Santis Antonio Meloni Massimo Miconi Contact: G. Dominici Tel fax dominici@ingv.it U.F. Geomagnetismo, Istituto Nazionale di Geofisica e Vulcanologia Via di Vigna Murata, Roma,Italy Austria Contact Person(s) Institution Gerald Duma Josef Berger Barbara Leichter gerald.duma@zamg.ac.at Central Institute for Meteorology and Geodynamics, Department of Geophysics, Hohe Warte 38, A 1190 Vienna, Austria Belarus Contact Person(s) Institution Elżbieta Welker Tel. (+48 22) , zgf@igik.edu.pl Institute of Geodesy and Cartography ul. Jasna 2/4, Warszawa, Poland Bulgaria Contact Person(s) Institution Ilia Cholakov B. Srebrov Geophysical Institute with Geomagnetic observatory, BAS Tel ; 32-31; Sofia 1113, Acad. G. Bouchev. st. block. 3, Bulgaria srebrov@geophys.bas.bg

21 21 Croatia Contact Person(s) Institution Mario Brkić Tel mario.brkic@geof.hr University of Zagreb, Faculty of Geodesy, Department for Geomatics Kačićeva 26, HR Zagreb, Croatia Czech Republic Contact Person(s) Pavel Hejda Josef Horacek Tel , jhor@ig.cas.cz Geophys. Institute, Acad. of Sci. GI, Bocui II, Prague Institution Estonia Contact Person(s) Institution Kari Pajunpää Tel: Fax: kari.pajunpaa@fmi.fi Finnish Meteorological Institute, Nurmijärvi Geophysical Observatory FIN Rykk, Finland Finland Contact Person(s) Institution Kari Pajunpää Tel: Finnish Meteorological Institute, Nurmijärvi Geophysical Observatory Fax: FIN Rykk, Finland kari.pajunpaa@fmi.fi France Contact Person(s) Institution Stuart GILDER

22 22 François TRUONG Kader TELALI Institut de Physique de Globe de Paris 4 Place Jussieu Paris Germany Contact Person(s) Institution Monika Korte Tel monika@gfz-potsdam.de GeoForschungsZentrum Potsdam, Telegrafenberg, D Potsdam Hungary Contact Person(s) Institution András Csontos csontos@elgi.hu EÖTVÖS LORÁND GEOPHYSICAL INSTITUTE, Budapest H , Columbus u Italy, Sardinia, Corsica Contact Person(s) Guido Dominici Angelo De Santis Antonio Meloni Massimo Miconi Contact: G. Dominici Tel fax dominici@ingv.it Institution U.F. Geomagnetismo, Istituto Nazionale di Geofisica e Vulcanologia Via di Vigna Murata, Roma,Italy Ireland Contact Person(s) Institution Keith Lambkin

23 (0) keith.lambkin@met.ie Irish Meteorological Society Valentia Observatory, Cahersiveen, Co. Kerry, Ireland Latvia Contact Person(s) Institution Lubova Sulakova lubova.sulakova@lgia.gov.lv Andrejs Zjatkovs andrejs.zjatkovs@lgia.gov.lv Latvian Geospatial Information Agency Lithuania Contact Person(s) Institution Elżbieta Welker Tel. (+48 22) , Institute of Geodesy and Cartography zgf@igik.edu.pl ul. Jasna 2/4, Warszawa, Poland Macedonia Contact Person(s) Institution Sanja Panovska Todor Delipetrov todor.delipetrov@gmail.com University Sts. Cyril and Methodius Skopje Faculty of Mining and Geology Stip Goce Delcev Stip Macedonia Poland Contact Person(s) Institution Andrzej Sas-Uhrynowski Elżbieta Welker Tel. (+48 22) , Institute of Geodesy and Cartography ul. Jasna 2/4, Warszawa, Poland elzbieta.welker@igik.edu.pl Andrzej.Sas- Uhrynowski@igik.edu.pl

24 24 Romania Contact Person(s) Institution Crisan Demetrescu Tel: +40 (21) Tel/Fax: +40 (21) Institute of Geodynamics, J.-L. Calderon Str., Sector 2, R-70201, Bucharest 37, Romania Serbia and Montenegro Contact Person(s) Nenad Smiljanic Tel: +40 (21) Tel/Fax: +40 (21) Geomagnetic Institute Grocka, Yugoslavia Institution Slovakia Contact Person(s) Institution Magdalena Vaczyova Fridrich Valach Tel Geophysical Institute of Slovak Academy of Sciences (GPI SAS) Geomagnetic Observatory Hurbanovo Komárnanská 108, Hurbanovo, Slovakia Spain Contact Person(s) Institution Isabel Socias Tel Servicio de Geomagnetismo Sub.Gral. Astronomia, Geodesia y Geofisica, Instituto Geografico Nacional, Madrid, Espana Switzerland Contact Person(s) Institution P.A. Schnegg pierre.schnegg@unine.ch Swiss Geophysical Commission, ETH-Zürich

25 25 United Kingdom Contact Person(s) Susan Macmillan Thomas Shanahan Tel. 44(0) Institution British Geological Survey Murchison Ho., West Mains Rd., Edinburgh, United Kingdom Ukraine Contact Person(s) Institution Valentin.Maksymchuk Yuriy Gorodysky Carpathian Branch of Subbotin Institute of Geophysics, National Academy of Sciences of Ukraine, Valtentina Kusnetsova Naukova str., 3-b, Lviv, Ukraine, Tel.: +380 (322)