Absolute Gravity Networks in South Absolute Gravity Networks in South

America - First Results and America - First Results and

perspectivesperspectivesDenizar Blitzkow

Ana Cristina O. Cancoro de Matos(dblitzko@usp.br)

EPUSP - Escola Politécnica da Universidade de São Paulo, Brasil

EPUSPEPUSPEscola Politécnica da Universidade de São PauloEscola Politécnica da Universidade de São Paulo

Worshop MicrogLacosteSep 2014Sep 2014

1

Earth Tide ModelEarth Tide Model

A project in BrazilA project in Brazilunder the coordination ofunder the coordination of

EPUSP/LTG and CENEGEO EPUSP/LTG and CENEGEO (Centre for Geodesy Studies) (Centre for Geodesy Studies)

to establish an Earth Tide Model to establish an Earth Tide Model

Support:GEORADAR Levantamentos Geofísicos S.A.

The first phase of the project is intended to achieve the determination of a preliminary model for the Earth tide in São Paulo state (four stations).

The project aims to establish 9 stations well distributed in Brazil:

One of long term in Manaus, Amazon.

Eight others in a sequence of four years operation in different places. In all cases a permanent GPS receiver is available.

gPhone Micro-g LaCoste 105 – Presidente Prudente - UNESP

During the year 2012 the two gPhones were installed respectively:1. University of São Paulo, São Paulo city;2. Abrahão de Moraes observatory, Valinhos city.The places belong to the Institute of Astronomy, Geophysics and Atmospheric Sciences of the University of São Paulo (IAG-USP).

Year 2013/20141. Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), in Presidente Prudente;2. The ocean research base Dr. João de Paiva Carvalho, Oceonographic Institute, University of São Paulo (IO-USP), located in Cananeia.3. University of São Paulo, São Paulo city;

We are using TSOFT and ETERNA softwares for the preparation of the data and for tidal analysis. After many problems for processing teh data we came to important improvement very recently.

The atmospheric pressure showed a perfect behavior considering that it varies inversely proportional to the gravity. A regression analysis applied to the observed pressure data resulted in a coefficient of 2.69. It is necessary to remove this effect from the gravity data.

The drift of the equipment was very small. The estimation of the drift by a regression analysis resulted in the following coefficients for the first order linear equation:

g = 5.58158 x10-13 T - 0.000224227whereg gravity valueT time

This drift can be studied with the absolute gravitymeter A-10, now available.

IAG-USP(January to October, 2012)

ambient pressure

data survey

Latitude:-25.0202 deg, longitude:-47.9250 deg, 20130314...20140108 Hartmann+Wenzel (1995) TGP Rigid Earth model used.Sampling interval: 300. s Numerical filter is N05M05M2 with 2001 coefficients.

Standard deviation: 43.548 nm/s**2

wave ampl. ampl.fac. stdv. ph. Lead stdv.  nm/s**2 nm/s**2 nm/s**2 deg deg

Q1 43.5419 1.1703 0.0255 -2.6759 1.2499O1 227.4148 1.1649 0.0061 -2.4218 0.3010M1 17.8759 1.1035 0.0641 -3.5965 3.3110K1 319.6977 1.1515 0.0040 -0.8067 0.1981J1 17.8824 1.1941 0.0703 -1.0152 3.3640OO1 9.7820 1.3041 0.1428 -2.0101 6.27462N2 19.2922 1.1467 0.0199 2.8625 0.9930N2 120.7935 1.1848 0.0051 -0.2420 0.2448M2 630.8874 1.1668 0.0011 -0.0530 0.0554L2 17.8339 1.2148 0.0407 -3.4183 1.9215S2 293.4950 1.1665 0.0025 0.2309 0.1208M3M6 11.3582 1.2085 0.0515 -0.5252 2.4433

IAG-USP

Abrahão de Moraes Observatory /IAG– Valinhos/SP(April to December, 2012)

ambient pressure

data survey

wave ampl. ampl.fac. stdv. ph. Lead stdv.  nm/s**2 nm/s**2 nm/s**2 deg deg

Q1 42.7537 1.2981 0.0705 -3.6385 3.1151O1 223.2982 1.1622 0.0146 -1.6254 0.7233M1 17.5523 1.0024 0.2116 15.5836 12.1173K1 313.9115 1.1432 0.0106 -0.2372 0.5322J1 17.5587 1.1345 0.1853 -17.9578 9.3412OO1 9,6049 1.2007 0.4100 -0.5046 19.58422N2 19.4520 1.2649 0.0616 0.7926 2.7994N2 121.7940 1.1610 0.0130 0.3981 0.6401M2 636.1128 1.1698 0.0027 1.8014 0.1298L2 17.9816 1.3614 0.0999 5.7975 4.2089S2 295.9259 1.1686 0.0054 2.3626 0.2653M3M6 11.4994 1.1275 0.0839 9.1482 4.2633

Latitude:-23.0042 deg, longitude:-46.9646 deg 20120409...20121223Hartmann+Wenzel (1995) TGPRigid Earth model used.Sampling interval: 300. sNumerical filter is N05M05M2 with 2001 coefficients.

Standard deviation: 39.253 nm/s**2

Abrahão de Moraes Observatory /IAG – Valinhos/SP

ambient pressure

data survey

UNESP – Presidente Prudente/SP(August, 2013 to January, 2014)

wave ampl. ampl.fac. stdv. ph. Lead stdv.  nm/s**2 nm/s**2 nm/s**2 deg deg

Q1 41.4525 1.2211 0.0907 -1.5052 4.2608O1 216.5014 1.1781 0.0185 -1.6106 0.9039M1 17.0185 1.0881 0.2791 0.2288 14.8115K1 304.3652 1.1634 0.0124 0.6652 0.6060J1 17.0245 1.2700 0.2407 2.3776 10.7170OO1 9.3108 1.1395 0.6614 22.2026 33.03222N2 19.7017 1.1529 0.1085 3.6901 5.4035N2 123.3575 1.1900 0.0239 1.7685 1.1583M2 644.2780 1.1716 0.0049 1.1336 0.2366L2 18.2124 1.2844 0.1859 5.9022 8.2442S2 299.7252 1.1760 0.0101 1.1936 0.4905M3M6 11.7210 1.1531 0.1426 8.3931 7.0988

Latitude:-22.1199 deg, longitude:-51.4085 deg, 20130720...20140120 Hartmann+Wenzel (1995) TGPRigid Earth model used.Sampling interval: 300. sNumerical filter is N05M05M2 with 2001 coefficients.

Standard deviation: 26.669 nm/s**2

UNESP – Presidente Prudente/SP

Dr. João de Paiva Carvalho Observatory/IO – Cananéia/SP

(April, 2013 to January, 2014)

20–22/09

wave ampl. ampl.fac. stdv. ph. Lead stdv.  nm/s**2 nm/s**2 nm/s**2 deg deg

Q1 45.5494 1.2024 0.0143 -1.4907 0.6806O1 237.8999 1.1664 0.0030 -1.7919 0.1474M1 18.7000 1.1094 0.0498 -1.0047 2.5739K1 334.4386 1.1346 0.0020 -05879 0.0998J1 18.7069 1.2070 0.0380 0.2496 1.8020OO1 10.2330 1.3181 0.1041 8.3092 4.53112N2 18.8513 1.1843 0.0129 4.4161 0.6246N2 118.0328 1.1841 0.0027 2.0118 0.1305M2 616.4687 1.1632 0.0005 2.4120 0.0268L2 17.4263 1.2076 0.0215 6.1065 1.0209S2 286.7873 1.1685 0.0012 2.7657 0.0572M3M6 10.9707 1.2345 0.0172 -3.2857 0.7991

Dr. João de Paiva Carvalho Observatory/IO – Cananéia/SP

Latitude:-25.0202 deg, longitude:-47.9250 deg 20130314...20140108 Hartmann+Wenzel (1995) TGP, Rigid Earth model used.Sampling interval: 300. s Numerical filter is N05M05M2 with 2001 coefficients.

Standard deviation: 16.41 nm/s**2

Absolute GravityAbsolute GravityA project in Brazil and ArgentinaA project in Brazil and Argentina

under the coordination ofunder the coordination of EPUSP/LTG and CENEGEO EPUSP/LTG and CENEGEO

(Centre for Geodesy Studies) (Centre for Geodesy Studies)

Support:

IGC (Instituto Geográfico e Cartográfico) in Brazil IGN (Instituto Geográfico Nacional) in Argentina

Importance of establishing more absolute stations in South America.

Source:http://bgi.get.obs-mip.fr/agrav-meta/

Absolute gravitymeter Micro-g LaCoste A-10/32

Astronomical ObservatoryValinhos - SP

The A-10 absolute gravimeter is working around Brazil and Argentina establishing fundamental gravity points with high precision and it will be used for controlling the drift of the gPhone when necessary.

Projects:

1. São Paulo state project (2013/2014):

- Stations established: Franca, Jaboticabal, Lins, São Carlos, São José do Rio Preto, Valinhos.- Reobservation of São Paulo, Ubatuba and Cananéia existing absolute points.- New stations will be established in Araçatuba, Botucatu, Cachoeira Paulista, Campinas, Dracena, Itapeva, Ilha Solteira, Tupã, Ourinhos, Presidente Prudente.

Results – UNESP Jaboticabal Station

Program interface with the result of 1 cycle and 120 drops "free fall"

Screen with the results

It is considered a very good

measurements, with a few

rejections in red. At each station 8

cycles of 120 drops are carried out.

6

)212( surveyfinal ggradientnewg

5,70* .

difHeight

gggradientnew topobase

The gravity gradient is observed in each station by measurements in two points

with the possible difference of height available. CG5 is used for the gradient

measurement. We don’t have a platform. In a first step the normal gradient

0.30 mGal/m is used. In a new processing the real gradient is taking into

consideration.

where:

Calculating the g value

Results of Sao Paulo state absolute stations

City ID Latitude Longitude final g(μGal)Jaboticabal JABOTICABAL -21.24056 -48.28750 978512730S. J. do R.

PretoS J R PRETO -20.78417 -49.36250 978516376

Lins LINS -21.67528 -49.75167 978589550Franca FRANCA -20.53583 -47.39917 978393382

São Carlos SÃO CARLOS -22.01139 -47.89667 978490175São Paulo 18_11_13_IAG -23.55900 -46.73400 978642071Valinhos VALINHOS -23.55889 -46.73389 978563961

Results of Parana state absolute station

City ID Latitude Longitude final g(μGal)Foz de Iguaçu 3FRONT -25.59028 -54.59028 978916210

  JABOTICABAL S J R PRETO LINS FRANCA SÃO CARLOS SÃO PAULO SÃO PAULO 2 VALINHOSG GROUND (microGal) 978513400 978516524 978590004 978393162 978489991 978641940 979999146 980000145G TOP (microGal) 978513021 978516271 978589801 978392989 978489795 978641746 979998960 979999834HEIGHT (cm) 120 97 73 55 65 67 67 80GRAD. (microGal/cm) 3,1583 2,6082 2,7808 3,1455 3,0154 2,8955 2,7761 3,8875G ABS. (microGal) 978512508 978516192 978589354 978393160 978489963 978641871 978641871 978563687New GRAD (microGal) 223 184 196 222 213 204 196 274,07

G FINAL COR. (microGal) 978512730 978516376 978589550 978393382 978490175 978642075 978642066 978563961

Gravity Gradient in São Paulo

FOZ DO IGUA.G GROUND (microGal) 978915970G TOP (microGal) 978915797HEIGHT (cm) 65GRAD. (microGal/cm) 2,6615G ABS. (microGal) 978916023GRAD. NEW (microGal) 188G FINAL COR. (microGal) 978916210

Garavity Gradient in Paraná

Station Old survey G value New survey G value

CG5-513

IAG USP Absolute 978641.82 (Absolute G value station IAG USP)

--------------------------------

121582 - Sorocaba B 978652.67 (Reference station determined by ON with L&R

gravimeter)

978652.64 (Determined by Scintrex CG5 gravimeter)

CG5 - 808

IAG USP Absolute 978641.82 (G value of the IAG USP Absolute station)

-------------------------------

11776 – Porto Ferreira B 978546.54 (Reference station determined by ON with L&R

gravimeter)

978546.47 (Determined by Scintrex CG5 gravimeter)

12176 – Ituverava B 978467.16 (Reference station determined by ON with L&R

gravimeter)

978467.05 (Determined by Scintrex CG5 gravimeter)

CG5 - 757

IAG USP Absoluta 978641.82 (G value of the IAG USP Absolute station) --------------------------------

12176 – Ituverava B 978467.16 (Reference station determined by ON with L&R gravimeter)

978466.98 (Determined by Scintrex CG5 gravimeter)

CG5 - 808

Lins Absoluta 978589.35 (G value of the Absolute station determined by USP)

978589.41 (Determined by the IAG USP with L&R gravimeter)

Franca PC 978394.62 (Departure of Franca absolute station - Determined by

Scintrex CG5 gravimeter)

978394.51 (Determined by IBGE - Departing from ON station in

Porto Ferreira B - Determined by Scintrex CG5 gravimeter)

Comparative Table

Monography for Jaboticabal station - UNESP

0004 UNESP JABOTICABAL BRASIL

Número da Estação Nome da Estação País

ESQUEMAEstado :

Estabelecido por :

Data :

Valor de G:

Coordenadas:

DESCRIÇÃOUtilizou-se um gradiente de 0,317 mGal/m para reduzir o valor obtido na altura da câmera de queda livre para o piso.

Detalhe

Panorama

SÃO PAULO

LTG / IGC / USP

03 / 10 / 2013

978512523,12 ± 11 μGal

Lat 21º 14’ 26” S

H = 596 m

Lon 48º 17’ 15” W

8

2. Argentina project:

2 campaigns: North (17 points) South (15 points)

Results of absolute stations in Argentina1st. Campaign (17 points)

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City ID Station Latitude Longitude final g(μGal)Colon GGIL -32.21656 -58.14703 979517779

El Zonda ZOND -31.54531 -68.68414 ?????Ituzaingo ITUZ -27.58425 -56.68681 979122746La Rioja RIOJ -29.42533 -66.86225 979042377

Lag. Yema LYEM -24.28083 -61.23633 978882640Mendonza MDZA -32.89361 -68.87667 979199554Mercedes MERC -29.22711 -58.07256 979239943

Puerto Iguazu IGUA -25.63833 -54.53889 978905477Quimili QUIM -27.64492 -62.41378 979123328Rosario ROSA -32.94783 -60.63058 979548444

San Cristobal SCRI -30.31000 -61.24228 979327540S. Lor. Salta SLOR -24.72131 -65.50464 978409390

San Luis SALU -33.12083 -66.02528 979316984Tucumán TUCU -26.84342 -65.23019 978886037

Tandil TAND -37.32353 -59.08200 979903711Victoria Mac. VMKA -33.91650 -64.36811 979580004

Vila Maria VMAR -32.40939 -63.21667 979473582

GGIL EL ZONDA EL ZONDA 1 ITUZAINGO LA RIOJAG GROUND (microGal) 980000323 980000134 980000134 980000286 980000144G TOP (microGal) 980000004 980000002 980000002 980000002 980000003HEIGHT (cm) 107 58 58 105 66GRAD. (microGal/cm) 2,9813 2,2759 2,2759 2,7048 2,1364G ABS. (microGal) 979517569 979141513 979141474 979122555 979042226GRAD. NEW (microGal) 210 160 160 191 151G FINAL COR. (microGal) 979517779 979141673 979141635 979122746 979042377

LAG.YEMA MENDONZA MERCEDESPUER.IGUAZU QUIMILIG GROUND (microGal) 980000233 980000234 980000388 980000228 980000351G TOP (microGal) 979999996 980000011 979999999 980000000 980000003HEIGHT (cm) 81 80 127 90 117GRAD. (microGal/cm) 2,9259 2,7875 3,0630 2,5333 2,9744G ABS. (microGal) 978882434 979199358 979239727 978905298 979123118GRAD. NEW (microGal) 206 197 216 179 210G FINAL COR. (microGal) 978882640 979199554 979239943 978905477 979123328

1st. Campaign in Argentina

ROSARIO SAN CRISTOB. SLOR. SALTA SAN LUIS TUCUMANG GROUND (microGal) 980000279 980000331 980000225 980000177 980000233G TOP (microGal) 980000007 980000008 980000012 980000002 980000006HEIGHT (cm) 105 109 83 61 81GRAD. (microGal/cm) 2,5905 2,9633 2,5663 2,8689 2,8025G ABS. (microGal) 979548262 979327331 978409209 979316782 978885840GRAD. NEW (microGal) 183 209 181 202 198G FINAL COR. (microGal) 979548444 979327540 978409390 979316984 978886037

TANDIL VIC.MACKEN. VILA MARIAG GROUND (microGal) 980000282 980000241 980000091G TOP (microGal) 980000020 980000001 980000000HEIGHT (cm) 96 78 37GRAD. (microGal/cm) 2,7292 3,0769 2,4595G ABS. (microGal) 979903519 979579788 979473409GRAD. NEW (microGal) 192 217 173G FINAL COR. (microGal) 979903711 979580004 979473582

1st. Campaign in Argentina

Results of absolute stations in Argentina2nd. Campaign (15 points)

City ID Station Latitude Longitude final g(μGal)Corrientes   -45.82472 -67.46361 979165409Payssandu (Uruguai)

PAYS -32.37889 -58.03056 979523524

Miguelete IGN01 -34.57694 -58.51667 979688254Bahia Blanca BHBL -38.66750 -62.23250 980046225Perito Moreno PERI1 -46.58972 -70.92639 980624557

Tres Lagos TRES -49.59861 -71.44500 980959909La Esperanza ESPE -51.02972 -70.77722 981084686

San Julian UNPA -49.29972 -67.77167 980993919Comodoro Rivadavia

CORI -45.82472 -67.46361 980663757

Rawsom RAWS -43.29944 -65.10722 980458034Esquel ESQU1 -42.89833 -71.29694 980231722

Neuquen NUQN -38.96278 -68.09806 979965694Victorica VICA1 -36.21694 -65.43667 979752736Roberts ROBE -35.14083 -61.97278 979723692

2nd. Campaign in Argentina

SLOR CORRI PAYSSANDU MIGUELETE MIGUELETE 1 BAHIA BLANCAG GROUND (microGal) 980000280 980000328 980000285 980000285 980000070G TOP (microGal) 980000002 980000002 980000001 980000001 979999994HEIGHT (cm) 88 106 94 94 31GRAD. (microGal/cm) 3,1591 3,0755 3,0213 3,0213 2,4516G ABS. (microGal) 979165187 979523307 979688041 979688027 980046052GRAD. NEW (microGal) 223 217 213 213 173G FINAL COR. (microGal) 979165409 979523524 979688254 979688240 980046225

PERITO MORENO TRES LAGOSLA ESPERANZASAN JULIANCOMODORO RIVADAVIAG GROUND (microGal) 980000211 980000212 980000087 980000255 980000146G TOP (microGal) 980000000 980000000 980000000 980000002 980000005HEIGHT (cm) 72 81 39 84 52GRAD. (microGal/cm) 2,9306 2,6173 2,2308 3,0119 2,7115G ABS. (microGal) 980624350 980959724 981084529 980993706 980663566GRAD. NEW (microGal) 207 185 157 212 191G FINAL COR. (microGal) 980624557 980959909 981084686 980993919 980663757

RAWSOM ESQUEL NEUQUEM VICTORICA ROBERTSG GROUND (microGal) 980000241 980000258 980000609 980000212 980000078G TOP (microGal) 980000003 980000002 980000003 979999999 980000001HEIGHT (cm) 76 93 336 77 35GRAD. (microGal/cm) 3,1316 2,7527 1,8036 2,7662 2,2000G ABS. (microGal) 980457814 980231528 979965567 979752541 979723537GRAD. NEW (microGal) 221 194 127 195 155G FINAL COR. (microGal) 980458034 980231722 979965694 979752736 979723692

The work shows the initial efforts to implement absolute gravimetric networks in South America.

We had many problems with A-10 since the begining. Derek visited us twice. In a first visit to set up A-10. He realized that it was not working. A repair has been necessary. The campaign in Argentina was very complicated: hot in the north (40º C) and very cold in the south.After the first campaign in Argentina we had problem with the two pendulums. The oil inside was lost. They have been substituted. Immediately after the autolevel switch failed. In all cases Derek and Brian were very helpful, At the moment the problem is with low fringes message. With the training I had in the last two days I could see the many different points I have to check. I hope to do it in my way back to Brazil and continue with my projects.

- Network in the sate of São Paulo, Paraná and Minas Gerais in Brazil.- A network in Venezuela and Ecuador.

- Network in the state of Paraná

We do not have yet a consistency on the order of 10μGal in our measurements. In Argentina we reoccupied a few points with BGI equipement. The differences are over 10 μGal.

We have a few absolute stations in Brazil established in the past by the group in Hannover and after by NGS (Daniel). I am now doing some comparisons.

AcknowledgementsAcknowledgements

The authors acknowledge Instituto Geográfico e Cartográfico (IGC) of São Paulo

to have available the absolute gravimeter for the realization of networks and the

Instituto Geográfico Nacional of Argentina that cooperated with the campaigns.

Absolute gravity – Vehicle used

Absolute gravity – Interior of the vehicle