Hans-Georg Scherneck

Hans-Georg Scherneck
Chalmers University of Technology · Department of Earth and Space Sciences

Docent

About

102
Publications
12,872
Reads
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2,460
Citations
Additional affiliations
August 1993 - present
Chalmers University of Technology
Position
  • Professor (Associate)
January 1984 - July 1993
Uppsala University
Position
  • PostDoc Position

Publications

Publications (102)
Article
We employ the barotropic, data-unconstrained ocean tide model TiME to derive an atlas for degree-3 tidal constituents including monthly to terdiurnal tidal species. The model is optimized with respect to the tide gauge data set TICON-td that is extended to include the respective tidal constituents of diurnal and higher frequencies. The tide gauge v...
Article
Full-text available
Ten-year worth of absolute gravity (AG) campaigns at Onsala Space Observatory (OSO), Sweden, are simultaneously reduced using synchronous data from a superconducting gravimeter (SG). In this multi-campaign adjustment, the a priori models commonly applied for each setup in AG-alone experiments are sidestepped in favour of SG records and a model to e...
Preprint
Preparing for joint analysis of absolute gravity (AG) campaigns, this report investigates whether a stationary superconducting gravimeter (SCG) can provide a long-term stable measurement of site-dependent perturbations that help in reduction to the local value of little-$g$ and its secular rate of change. The crucial element concerns the discrimina...
Article
Full-text available
Changes of surface gravity on Earth are of great interest in geodesy, earth sciences and natural resource exploration. They are indicative of Earth system's mass redistributions and vertical surface motion, and are usually measured with falling corner-cube- and superconducting gravimeters (FCCG and SCG). Here we report on absolute gravity measureme...
Presentation
Full-text available
Atom interferometers have demonstrated a high sensitivity to accelerations and rotations. This enables their application in gravimetry, creating a new type of instrument for continuous absolute gravity measurements. The Gravimetric Atom Interferometer (GAIN) is a mobile atom interferometer based on interfering ensembles of laser-cooled Rb-87 atoms...
Article
Annual absolute gravity measurements with a FG5 instrument were performed in Onsala Space Observatory by the Institute of Geodesy of the Leibniz Universität Hannover from 2003 to 2011 and have been continued with the upgraded meter FG5X in 2014. Lantmäteriet, Gävle, with their FG5 absolute gravimeter have visited Onsala since 2007. Because small sy...
Article
Full-text available
Annual absolute gravity measurements with a FG5 instrument were performed in Onsala Space Observatory by the Institute of Geodesy of the Leibniz Universität Hannover from 2003 to 2011 and have been continued with the upgraded meter FG5X in 2014. Lantmäteriet, Gävle, with their FG5 absolute gravimeter have visited Onsala since 2007. Because small sy...
Data
Very Long Baseline Interferometry (VLBI) is a primary space-geodetic technique for determining precise coordinates on the Earth, for monitoring the variable Earth rotation and orientation with highest precision, and for deriving many other parameters of the Earth system. The International VLBI Service for Geodesy and Astrometry (IVS, http://ivscc.g...
Article
Full-text available
We present sea level observations derived from the analysis of Signal-to-Noise Ratio (SNR) data recorded at five coastal GPS sites. These sites are located in different regions around the world, both in the northern and the southern hemisphere, in different multipath environments, from rural coastal areas to busy harbors, and experience different t...
Article
The rate of change of surface gravity, , and vertical deformation rate of the solid surface, , are two observables of glacial isostatic adjustment (GIA). They contribute with different information on the same phenomenon. Their relation contains information of the underlying physics and a trustworthy relation allows to combine these observations to...
Article
Full-text available
The Earth deforms periodically due to the varying weight of the ocean tides. Classical terrestrial geodetic techniques such as gravimetry, strain and tilt observe this deformation clearly. Also space geodetic techniques have reached an accuracy level where this loading signal can no longer be ignored. We present here the basic physical assumptions...
Article
Full-text available
Northern Fennoscandia bears witness to the Pleistocene glaciation in the form of a series of large faults that have been shown to have ruptured immediately after the retreat of the ice sheet, about 9500 years ago. The largest one, known as the Pärvie fault, consists of a 155 km long linear series of fault scarps forming north–northeast-trending, th...
Article
Global sea level rise and local sea level variations due to climate change is believed to significantly impact coastal societies during this century. Thus, it is of great importance to monitor and understand how the sea level is changing. Existing techniques to measure sea level, e.g., tide gauges and altimeters, have provided important insights in...
Article
This paper deals with the modelling of surface gravity change in Fennoscandia, induced by postglacial rebound or Glacial Isostatic Adjustment (GIA). The theoretical foundation is based on the theory introduced by 0150 and 0155 for a spherical, non-rotating, laterally homogenous, viscoelastic, Maxwell Earth and the solution of the Sea Level Equation...
Chapter
Full-text available
This chapter will discuss the computation of the deformation of the solid Earth due to external forces. It is a classical problem that was studied more than a century ago by famous people such as Thomson and Tait (1867) and Lamb (1895). They were followed by Love (1911) and Hoskins (1920) in the beginning of the twentieth century. Since then it has...
Article
Full-text available
The goal of the Global Geodetic Observing System (GGOS) is to monitor the Earth system, in particular with observations of the three fundamental geodetic observables: the Earth's shape, the Earth's gravity field and the Earth's rotational motion. A central part of GGOS is the network of globally distributed fundamental geodetic stations that allow...
Article
We use standard geodetic Global Navigation Satellite System (GNSS) equipment to perform remote sensing measurements of the coastal ocean. This is done by a so-called GNSS-based tide gauge that uses both direct GNSS-signals and GNSS-signals that are reflected off the sea surface. Our installation is located at the Onsala Space Observatory (OSO) at t...
Article
Full-text available
The Pärvie postglacial fault is a 155 km long fault that probably snapped in one single and anomalously steep reverse-slip event at the end of the Pleistocene glaciation about 9,500 ybp. Still today the seismicity, limited to roughly one magnitude-3.5 event per 15 years, one M=2 event per year, is anomalous and events have been attributed to the fa...
Article
Full-text available
By receiving Global Navigation Satellite System (GNSS) signals that are reflected off the sea surface, together with directly received GNSS signals (using standard geodetic-type receivers), it is possible to monitor the sea level using regular single difference geodetic processing. We show results from our analysis of three months of data from the...
Conference Paper
Full-text available
Global Navigation Satellite System (GNSS) signals re-flected off the sea surface can be used for remote sensing of the sea level. We present results from a GNSS-based tide gauge using standard geodetic-type GNSS receivers for receiving both the reflected and the direct GNSS sig-nals. The local sea level is then obtained using relative geodetic proc...
Article
Full-text available
In continental plate interiors, ground surface movements are at the limit of the noise level and close to or below the accuracy of current geodetic techniques. Absolute gravity measurements are valuable to quantify slow vertical movements, as this instrument is drift free and, unlike GPS, independent of the terrestrial reference frame. Repeated abs...
Article
We present the latest 3D velocity field of the Fennoscandian glacial isostatic adjustment (GIA) process from BIFROST. It is derived from more than 4800 days (13 years) of data at more than 80 permanent GPS sites. We use the GAMIT/GLOBK and the GIPSY/OASIS II software packages for GPS analysis and compare the results. The solution has an internal ac...
Article
The aim of this investigation is to develop a method for the analysis of crustal strain determined by station networks that continuously measurements of Global Navigation Satellite Systems (GNSS). The major new ingredient is that we require a simultaneous minimum of the observation error and the elastic and potential energy implied by the deformati...
Article
The main purpose of this paper is to investigate numerically the effects of non-tidal sea level variations in the Baltic Sea on gravity with special emphasis on the Swedish stations in the Nordic Absolute Gravity Project.To calculate the ocean loading effect on gravity the method described by Farrell (1972) is widely used. This method is based on c...
Conference Paper
Full-text available
Measurement of co-seismic strong-motion displacements at sub-second temporal resolution is of great importance for earthquake studies. We have investigated the usage of high-rate sampled Global Navigation Satellite System (GNSS) data to measure seismic motion by implementing an industrial robot simulating the displacements close to an earthquake ep...
Conference Paper
Full-text available
GNSS-observations are today used to investigate a variety of research topics in geosciences, including e.g. monitoring of crustal deformations and the amount of tropospheric water vapour. These applications require high accuracy for the results, e.g. millimeter-accuracy for positioning. During the last years so-called absolute antenna calibrations...
Article
Full-text available
GNSS-observations are today used to investigate a variety of research topics in geosciences, including e.g. monitoring of crustal deformations and the amount of tropospheric water vapour. These applications require high accuracy for the results, e.g. millimeter-accuracy for positioning. During the last years so-called absolute antenna calibrations...
Article
We analyze several years of GPS data recorded with roof-top stations in Gothenburg (Sweden) and permanent stations of the Swedish national reference network in the larger Gothenburg region. The derived station positions of several of the roof-top stations in Gothenburg reveal periodic horizontal motions with amplitudes of several millimeters and pe...
Chapter
Full-text available
The isostatic adjustment of the solid Earth to the glacial loading (GIA, Glacial Isostatic Adjustment) with its temporal signature offers a great opportunity to retrieve information of Earth’s upper mantle to the changing mass of glaciers and ice sheets, which in turn is driven by variations in Quaternary climate. DynaQlim (Upper Mantle Dynamics an...
Article
Full-text available
The accuracy of ocean tide loading (OTL) displacement values has long been assumed to be dominated by errors in the ocean tide models used, with errors due to the convolution scheme used considered very small (2–5%). However, this paper shows that much larger convolution errors can arise at sites within approximately 150km of the coastline, dependi...
Chapter
We present new and improved 3D velocity fields of the Fennoscandian Glacial Isostatic Adjust- ment (GIA) process derived from more than 4800 days (13 years) of data at more than 80 permanent GPS sites. We use the GAMIT/GLOBK software package for the GPS analysis. The solution has an internal accuracy at the level of 0.2 mm/yr (1 sigma) for horizont...
Conference Paper
Full-text available
In Europe, the Nordic countries Norway, Sweden, Denmark and Finland are a key study region for the research of glacial isostasy, and, in addition, it offers a unique opportunity for validating and evaluation of the results of the gravity satellite mission GRACE. Over a period of five years a temporal geoid variation of 3.0 mm is expected in the cen...
Article
The diurnal and semi-diurnal variability of the integrated precipitable water vapour (IPWV) was studied by using Global Positioning System (GPS) data (1998–2004) from 14 International GNSS Service (IGS) stations located between latitudes 20°S and 20°N, and longitudes 70° –170°E. The phases and amplitudes of the IPWV are compared to the correspondin...
Article
An observation model for earth tide displacements in application to Very Long Baseline Interferometry and similar precise geodetic techniques is developed. It incorporates effects from anelasticity, ellipsoidal figure, and fluid core resonance. Based on a harmonic development of the external potential, the model follows the familiar Love number con...
Article
Full-text available
We present a new GPS-derived 3D velocity field for the Fennoscandia glacial isostatic adjustment (GIA) area. This new solution is based upon ∼3,000days of continuous GPS observations obtained from the permanent networks in Fennoscandia. The period encompasses a prolongated phase of stable observation conditions after the northern autumn of 1996. Se...
Chapter
Full-text available
The Nordic Geodetic Observing System (NGOS) integrates fundamental geodetic techniques for the long-term observation of Earth system parameters. The Nordic Geodetic Commission (NKG) established a Task Force with the mission to prepare a document providing the definition and draft for the implementation of the NGOS. The regional system aligns with i...
Chapter
Full-text available
The BIFROST project uses GPS to observe the intra-continental deformation of Fennoscandia caused predominantly by Glacial Isostatic Adjustment (GIA). The noise in GPS position time series has been proven correlated, so we investigate a fractal model in order to obtain a parameter that can gauge our network stations true velocity uncertainties and u...
Conference Paper
Full-text available
The Nordic countries Norway, Sweden, Denmark and Finland are a key study region for the research of glacial isostasy, and, in addition, it offers a unique opportunity for validating and testing the results of GRACE. Over a period of five years a temporal geoid variation of 3.0 mm is expected in the centre of the Fennoscandian land uplift area, corr...
Chapter
Full-text available
The Nordic countries Norway, Sweden, Denmark and Finland are a key study region for the research of glacial isostasy, and, in addition, it offers a unique opportunity for validating and testing the results of the GRACE experiment. Over a period of five years, the expected life time of GRACE, a temporal geoid variation of 3.0 mm is expected in the c...
Article
We present a new improved 3D velocity field of the Fennoscandian Glacial Isostatic Adjustment (GIA) process derived from more than 3000 days at more than 50 permanent GPS sites. We use the GAMIT/GLOBK and the GIPSY/OASIS II software packages for GPS analysis. We compare the results from GAMIT/GLOBK, from GIPSY in PPP mode (Precise Point Positioning...
Article
This paper addresses the local displacement at ground stations of the world-wide Satellite Laser Ranging (SLR) network induced by atmospheric pressure variations. Since currently available modelling options do not satisfy the requirements for the target application (real-time availability, complete coverage of SLR network), a new representation is...
Article
The permanently recording BIFROST (Baseline Inferences for Fennoscandian Rebound Observations, Sea Level and Tectonics) GPS network was set into operation during the early to mid-1990s to monitor the three-dimensional crustal deformation field in Fennoscandia. We have employed 2500 days of BIFROST GPS data to estimate rates of baseline component ch...
Article
The land uplift processes in Fennoscandia have been subject to scientific research for more than a century. The cause of this land uplift phenomenon is a glacial isostatic adjustment (GIA) process, which has its origin in the last ice age that culminated about 20 kyr ago. In 1993, the Baseline Inferences for Fennoscandian Rebound Observations Sea L...
Article
Full-text available
Data collected under the auspices of the BIFROST GPS project yield a geographically dense suite of estimates of present-day, three-dimensional (3-D) crustal deformation rates in Fennoscandia [ Johansson et al., 2002 ]. A preliminary forward analysis of these estimates [ Milne et al., 2001 ] has indicated that models of ongoing glacial isostatic adj...
Article
Crustal deformations caused by surface load due to ocean tides are strongly dependent on the surface load closest to the observation site. In order to correctly model this ocean loading effect near irregular coastal areas, a high-resolution coastline is required. A test is carried out using two GPS sites located in Alaska, where the ocean tide load...
Article
This paper reports from investigations on the robustness of estimated rates of intraplate motion from the continuous GPS project BIFROST (Baseline Inferences from Fennoscandian Rebound Observations, Sealevel and Tectonics). We study loading effects due to ocean, atmosphere and hydrology and their impact on estimated rate parameters. We regularly fi...
Article
Postglacial rebound appears to be the dominant component of recent crustal motion in the Fennoscandian shield. From 3000 daily solutions of GPS data in the BIFROST network we have derived a map of strain rates in the interior of the shield with values typically below 10 nano/year. Examination of the strain field by means of a glacial isostatic adju...
Article
Project BIFROST (Baseline Inferences for Fennoscandian Rebound Observations Sea Level and Tectonics) was initiated in 1993 to directly measure the present-day, 3-D crustal deformation field in Fennoscandia [Johansson et al., JGR, 107, 2002; Milne et al., Science, { 291, 2001}]. A dense array of continuously operating GPS (Global Positioning System)...
Article
We present results on long-term trends of integrated precipitable water vapor (IPWV) over the Scandinavian region based on data from the Swedish permanent Global Positioning System (GPS) network, obtained during the period August 1993 to the end of 2000. We assess the magnitude of the effects on the estimated IPWV caused by antenna radome changes b...
Article
[1] Project BIFROST (Baseline Inferences for Fennoscandian Rebound Observations, Sea-level, and Tectonics) combines networks of continuously operating GPS receivers in Sweden and Finland to measure ongoing crustal deformation due to glacial isostatic adjustment (GIA). We present an analysis of data collected between August 1993 and May 2000. We com...
Article
Full-text available
Currently, the establishment of the International Earth Rotation Service (IERS) Special Bureau for Loading (SBL) is in progress as part of the IERS Global Geophysical Fluids Center (GGFC). The main purpose of the SBL is to provide reliable, consistent model predictions of loading signals that have been thoroughly tested and validated. The products...
Article
Full-text available
We describe the ingredients of an automatic service for the dissemination of ocean tide loading coefficients and the considerations that led to the solution employed. The paper reviews the surface loading problem, methods for computation and especially the improvement of coastline resolution for accurate representation of coastal loads. We finally...
Article
The current accuracy of absolute positioning using GPS cannot provide us with the desired subcentimeter precision over periods shorter than 24 hours. However, relative positioning using differential GPS (DGPS) has much higher accuracy and allows us to directly observe the differential ocean tide loading displacements between sites. Hence, in this s...
Article
We study load and solid earth tides using globally distributed continuous GPS data and models of ocean and solid earth tides. A two-step strategy is used to maintain reference frame consistency and to allow economical tidal determination for a large number of global sites. First, a fixed network of 45 sites with good geographic coverage and availab...
Article
From 2800 days of continuous GPS in Fennoscandia the BIFROST project estimates three-dimensional motion and intraplate deformation. This presentation will concen- trate on the vertical component. Adding the vertical crustal motion to tide gauge in- ferred relative sea level change, a regional term for global sea level change (RSLC) can be derived....
Article
We compute the strain rate field from Fennoscandian rebound observations using eight years of BIFROST continuous GPS. Three methods are employed: Triangulation (no overdetermination), polynomial approximation (overdetermined), and baseline com- ponents (low error bias). The results are compared with the strain rates from a model of glacial isostati...
Article
Crustal deformations caused by surface load due to ocean tides can be detected us- ing different geodetic techniques such as VLBI and GPS. However, when using GPS the troposphere must be modeled correctly without absorbing the ocean tide loading effect. In order to avoid absorption of ocean tide loading effect into the troposphere modeling, we have...
Article
Full-text available
Since 1990 the European fixed station geodetic Very Long Baseline Interferometry (VLBI) network has been observing on a regular basis in order to determine surface motion in Europe. During the first years the network was limited to central and southern Europe. With the inclusion of Ny-˚ Alesund on Spitsbergen and Simeiz on the Crimean peninsula it...
Article
Beginning in 1993 the BIFROST project has been compiling a large data base of geodetic positions using permanent networks of GPS receivers in Sweden and Finland, SWEPOS and FinnRef, respectively. The continuous GPS observation has provided a total of about 2500 daily solutions. From this data rates of change of, for instance, vertical position or i...
Article
Observations of 3-D crustal motion in Fennoscandia obtained via Project BIFROST (Baseline Inferences for Fennoscandian Rebound Observations, Sea Level and Tectonics) show a pattern that is clearly related to the on-going glacial isostatic adjustment (GIA) of the region. To predict the deformation field we adopt a GIA forward model comprised of a sp...
Article
Full-text available
Crustal deformations caused by surface load due to ocean tides are strongly dependent on the surface load closest to the observing site. In order to correctly model this ocean loading effect near irregular coastal areas, a high-resolution coastline is required. A test is carried out using two GPS sites located in Alaska, where the ocean tide loadin...
Article
Full-text available
The European geodetic VLBI network has been operating for 11 years and has demonstrated that space geodesy techniques now represent a powerful tool for understanding present-day geodynamics. In the last years research has been stressed on the improvement of accuracy and precision of VLBI observations and analysis in particular regarding the height...
Article
Full-text available
Since autumn 1993 the BIFROST project has provided daily GPS solutions of geodetic positions from a network of more than 40 stations covering a large area of the Baltic shield. This area is expected to show large vertical motion due to glacial isostatic rebound following the deglaciation at the end of the Pleistocene. This paper will discuss the in...
Article
Full-text available
Analysis of Global Positioning System (GPS) data demonstrates that ongoing three-dimensional crustal deformation in Fennoscandia is dominated by glacial isostatic adjustment. Our comparison of these GPS observations with numerical predictions yields an Earth model that satisfies independent geologic constraints and bounds both the average viscosity...
Article
Full-text available
Thanks to a parametrised solid earth tide model that efficiently (with a minimum set of parameters) describes the transfer response of the earth to the input tide potential in harmonic decomposition it is possible to obtain high-sensitivity in determination of the frequency and quality factor of the liquid core nearly-diurnal free nutation from obs...
Article
Full-text available
This short paper reports of loading effects considered in the continuous GPS project BIFROST (Baseline Inferences from Fennoscandian Rebound Observations, Sealevel and Tectonics). Effects due to ocean, atmosphere and hydrology are considered. We regularly find admittance of the modelled effects at less than fifty pecent of the full effect. We think...