A 200 km suspected impact crater Kotuykanskaya near Popigai, Siberia, in the light of new gravity aspects from EIGEN 6C4, and other data

We provide arguments in favour of impact origin of a 200 km suspected impact crater Kotuykanskaya near Popigai, Siberia, Russia. We use the gravity aspects (gravity disturbances, the Marussi tensor of the second derivatives of the disturbing geopotential, the gravity invariants and their specific ratio, the strike angles and the virtual deformations), all derived from the combined static gravity field model EIGEN 6C4, with the ground resolution of about 10 km and a precision of about 10 milliGals. We also use the magnetic anomalies from the model EMAG2 and emphasize the evidence of much deeper sources in the suspected area, constraining the impact origin of this structure.Web of Science101art. no. 609

Earth2014: 1 arc-min shape, topography, bedrock and ice-sheetmodels – Available as gridded data and degree-10,800 sphericalharmonics

Since the release of the ETOPO1 global Earth topography model through the US NOAA in 2009, new or significantly improved topographic data sets have become available over Antarctica, Greenland and parts of the oceans. Here, we present a suite of new 1(arc-min) models of Earth’s topography, bedrock and ice-sheets constructed as a composite from up-to-date topography models: Earth2014. Our model suite relies on SRTM30 PLUS v9 bathymetry for the base layer, merged with SRTM v4.1 topography over the continents, Bedmap2 over Antarctica and the new Greenland bedrock topography (GBT v3). As such, Earth2014 provides substantially improved information of bedrock and topography over Earth’s major ice sheets, and more recent bathymetric depth data over the oceans, all merged into readily usable global grids. To satisfy multiple applications of global elevation data, Earth2014 provides different representations of Earth’s relief. These are grids of (1) the physical surface, (2) bedrock (Earth’s relief without water and ice masses), (3) bedrock and ice (Earth without water masses), (4) ice sheet thicknesses, (5) rock-equivalent topography (ice and water masses condensed to layers of rock) as mass representation. These models have been transformed into ultra-high degree spherical harmonics, yielding degree 10,800 series expansions of the Earth2014 grids as input for spectral modelling techniques. As further variants, planetary shape models were constructed, providing distances between relief points and the geocenter. The paper describes the input data sets, the development procedures applied, the resulting gridded and spectral representations of Earth2014, external validation results and possible applications. The Earth2014 model suite is freely available via http://ddfe.curtin.edu.au/models/Earth2014/

La gravimetria da satellite come vincolo nelle stime di flusso di calore : primi risultati

Un confronto tra modelli globali di gravit\ue0 (quali quelli ottenuti dai dati del satellite GOCE) e mappe di flusso di calore in superficie -due osservabili geofisiche non legate da semplici leggi- suggerisce un legame tra anomalia di Bouguer e diversi regimi di trasporto del calore. In un quadro finalizzato a valutare quanto sia possibile quantificare in maniera rigorosa tale relazione, abbiamo verificato come un semplice modello in cui valga una relazione diretta spessore crostale - produzione radiogenica di calore in crosta continentale possa essere utilizzato per stimare la componente di flusso sub-continentale. A causa dei vincoli logistici ed economici associati alle misure dirette del flusso di calore, la distribuzione di queste non \ue8 omogenea: in particolare \ue8 presente un bias verso i flussi elevati, associato all'interesse per lo sfruttamento della risorsa geotermica ad alta entalpia. Persistono aree prive di misure anche in zone non remote dell'Europa centro-occidentale. Compensare questi vuoti d'informazione tramite interpolazione pu\uf2 comportare la sovrastima dell'estensione delle zone ad alto flusso. Una possibile strategia per ovviare a ci\uf2 \ue8 la separazione tra componenti di flusso a diverse profondit\ue0, con l'obiettivo di isolare le componenti pi\uf9 profonde (rappresentate dal flusso attraverso la base della crosta), alla quale sono associate lunghezze caratteristiche delle anomalie termiche misurate in superficie maggiori rispetto a quelle dovute a strutture pi\uf9 localizzate. Otteniamo questo tramite una strategia di backstripping, stimando la componente crostale del flusso con la profondit\ue0 di due interfacce crostali, usate come fattore di scala, ottenute tramite inversione del dato di gravit\ue0. Il risultato \ue8 una mappa di flusso a scala regionale (risoluzione di circa 100 km), che presentiamo in un area studio (includente Alpi e bacini adiacenti, massiccio renano, Graben del Reno), confrontandola col risultato di un'interpolazione non vincolata. Questo prodotto, meno suscettibile all'influenza di fenomeni locali, ha permesso di isolare i fattori e le criticit\ue0 su cui andr\ue0 indirizzata una pi\uf9 sofisticata modellazione

Tensor Marussi dan Pemodelan Gayaberat Inversi Tiga Dimensi (3D) untuk Membuktikan Patahan Watukosek dengan menggunakan Data EIGEN-6C4

Daerah Porong, Sidoarjo, adalah daerah semburan gunung api lumpur yang sering disebut LUSI (Lumpur Sidoarjo). Pada daerah tersebut terdapat kemungkinan adanya Patahan Watukosek yang membentang dari Gunung Penanggungan melewati pusat semburan LUSI sampai dengan Selat Madura. Penelitian ini bertujuan untuk membuktikan keberadaan patahan tersebut dengan menggunakan pemodelan gayaberat inversi tiga dimensi yang didukung dengan hasil interpretasi peta Tensor Marussi dari data EIGEN-6C4. Model EIGEN-6C4 adalah model geopotensial global yang memiliki anomali yang bersifat regional sehingga dalam menginterpretasi struktur geologi hanya hanya pada zona dalam. Pemodelan gayaberat inversi tiga dimensi dibuat dari data anomali bouguer regional yang menghasilkan model kontras densitas bawah permukaan yang memiliki struktur geologi perlipatan, graben, half-graben, dan patahan normal. sedangkan Tensor Marussi adalah turunan kedua dari disturbing potential dalam bentuk enam peta dua dimensi yang terdiri dari T_xx,T_xy,T_xz,T_yy,T_yz, dan T_zz. Struktur geologi daerah Jawa Timur di-interpretasi berupa patahan geser sinstral dengan jurus timur laut. Patahan watukosek di-interpretasikan di sebelah timur laut Gunung Penanggungan mengarah ke timur laut namun tidak terdapat kemenerusan sampai ke daerah gunungapi lumpur Gunung Anyar. =============================================================================================== Porong region, Sidoarjo, is the area of mud volcano eruption which often called LUSI (Lumpur Sidoarjo). In the area there is the possibility of Watukosek fault extending from Penanggungan Mountain passing through the center of LUSI towards Madura Strait. This study attempts to show the existence of that fracturing by three-dimensional gravity inversion modelling backed with the results of Marussi tensor map interpretation from EIGEN-6C4 data. EIGEN-6C4 is a model of global geopotential containing regional anomaly so that the interpretation of geological structure is only been done in the deep zone. Three-dimensional gravity inversion modelling is made from regional bouguer anomaly data that produced model of density contrast that has a geological structure of folding, grabens, half-grabens, and normal fault, while Tensor Marussi is a second derivative of disturbing potential that could describe the geological structures in the form of six two-dimensional maps consist of T_xx,T_xy,T_xz,T_yy,T_(yz,) and T_zz. The geologic structures is interpreted as a sinistral shear fault with strike towards northeast. The watukosek fault is interpreted in the north-east of Mount Penanggungan towards the northeast but there is no continuity until of Gunung Anyar mud volcano

Towards an International Height Reference System: insights from the Colorado geoid experiment using AUSGeoid computation methods

We apply the AUSGeoid data processing and computation methodologies to data provided for the International Height Reference System (IHRS) Colorado experiment as part of the International Association of Geodesy Joint Working Groups 0.1.2 and 2.2.2. This experiment is undertaken to test a range of different geoid computation methods from international research groups with a view to standardising these methods to form a set of conventions that can be established as an IHRS. The IHRS can realise an International Height Reference Frame to be used to study physical changes on and within the Earth. The Colorado experiment study site is much more mountainous (maximum height 4401 m) than the mostly flat Australian continent (maximum height 2228 m), and the available data over Colorado are different from Australian data (e.g. much more extensive airborne gravity coverage). Hence, we have tested and applied several modifications to the AUSGeoid approach, which had been tailored to the Australian situation. This includes different methods for the computation of terrain corrections, the gridding of terrestrial gravity data, the treatment of long-wavelength errors in the gravity anomaly grid and the combination of terrestrial and airborne data. A new method that has not previously been tested is the application of a spherical harmonic high-pass filter to residual anomalies. The results indicate that the AUSGeoid methods can successfully be used to compute a high accuracy geoid in challenging mountainous conditions. Modifications to the AUSGeoid approach lead to root-mean-square differences between geoid models up to ~ 0.028 m and agreement with GNSS-levelling data to ~ 0.044 m, but the benefits of these modifications cannot be rigorously assessed due to the limitation of the GNSS-levelling accuracy over the computation area

On High Performance Computing in Geodesy : Applications in Global Gravity Field Determination

Autonomously working sensor platforms deliver an increasing amount of precise data sets, which are often usable in geodetic applications. Due to the volume and quality, models determined from the data can be parameterized more complex and in more detail. To derive model parameters from these observations, the solution of a high dimensional inverse data fitting problem is often required. To solve such high dimensional adjustment problems, this thesis proposes a systematical, end-to-end use of a massive parallel implementation of the geodetic data analysis, using standard concepts of massive parallel high performance computing. It is shown how these concepts can be integrated into a typical geodetic problem, which requires the solution of a high dimensional adjustment problem. Due to the proposed parallel use of the computing and memory resources of a compute cluster it is shown, how general Gauss-Markoff models become solvable, which were only solvable by means of computationally motivated simplifications and approximations before. A basic, easy-to-use framework is developed, which is able to perform all relevant operations needed to solve a typical geodetic least squares adjustment problem. It provides the interface to the standard concepts and libraries used. Examples, including different characteristics of the adjustment problem, show how the framework is used and can be adapted for specific applications. In a computational sense rigorous solutions become possible for hundreds of thousands to millions of unknown parameters, which have to be estimated from a huge number of observations. Three special problems with different characteristics, as they arise in global gravity field recovery, are chosen and massive parallel implementations of the solution processes are derived. The first application covers global gravity field determination from real data as collected by the GOCE satellite mission (comprising 440 million highly correlated observations, 80,000 parameters). Within the second application high dimensional global gravity field models are estimated from the combination of complementary data sets via the assembly and solution of full normal equations (scenarios with 520,000 parameters, 2 TB normal equations). The third application solves a comparable problem, but uses an iterative least squares solver, allowing for a parameter space of even higher dimension (now considering scenarios with two million parameters). This thesis forms the basis for a flexible massive parallel software package, which is extendable according to further current and future research topics studied in the department. Within this thesis, the main focus lies on the computational aspects.Autonom arbeitende Sensorplattformen liefern präzise geodätisch nutzbare Datensätze in größer werdendem Umfang. Deren Menge und Qualität führt dazu, dass Modelle die aus den Beobachtungen abgeleitet werden, immer komplexer und detailreicher angesetzt werden können. Zur Bestimmung von Modellparametern aus den Beobachtungen gilt es oftmals, ein hochdimensionales inverses Problem im Sinne der Ausgleichungsrechnung zu lösen. Innerhalb dieser Arbeit soll ein Beitrag dazu geleistet werden, Methoden und Konzepte aus dem Hochleistungsrechnen in der geodätischen Datenanalyse strukturiert, durchgängig und konsequent zu verwenden. Diese Arbeit zeigt, wie sich diese nutzen lassen, um geodätische Fragestellungen, die ein hochdimensionales Ausgleichungsproblem beinhalten, zu lösen. Durch die gemeinsame Nutzung der Rechen- und Speicherressourcen eines massiv parallelen Rechenclusters werden Gauss-Markoff Modelle lösbar, die ohne den Einsatz solcher Techniken vorher höchstens mit massiven Approximationen und Vereinfachungen lösbar waren. Ein entwickeltes Grundgerüst stellt die Schnittstelle zu den massiv parallelen Standards dar, die im Rahmen einer numerischen Lösung von typischen Ausgleichungsaufgaben benötigt werden. Konkrete Anwendungen mit unterschiedlichen Charakteristiken zeigen das detaillierte Vorgehen um das Grundgerüst zu verwenden und zu spezifizieren. Rechentechnisch strenge Lösungen sind so für Hunderttausende bis Millionen von unbekannten Parametern möglich, die aus einer Vielzahl von Beobachtungen geschätzt werden. Drei spezielle Anwendungen aus dem Bereich der globalen Bestimmung des Erdschwerefeldes werden vorgestellt und die Implementierungen für einen massiv parallelen Hochleistungsrechner abgeleitet. Die erste Anwendung beinhaltet die Bestimmung von Schwerefeldmodellen aus realen Beobachtungen der Satellitenmission GOCE (welche 440 Millionen korrelierte Beobachtungen umfasst, 80,000 Parameter). In der zweite Anwendung werden globale hochdimensionale Schwerefelder aus komplementären Daten über das Aufstellen und Lösen von vollen Normalgleichungen geschätzt (basierend auf Szenarien mit 520,000 Parametern, 2 TB Normalgleichungen). Die dritte Anwendung löst dasselbe Problem, jedoch über einen iterativen Löser, wodurch der Parameterraum noch einmal deutlich höher dimensional sein kann (betrachtet werden nun Szenarien mit 2 Millionen Parametern). Die Arbeit bildet die Grundlage für ein massiv paralleles Softwarepaket, welches schrittweise um Spezialisierungen, abhängig von aktuellen Forschungsprojekten in der Arbeitsgruppe, erweitert werden wird. Innerhalb dieser Arbeit liegt der Fokus rein auf den rechentechnischen Aspekten

On high performance computing in geodesy : applications in global gravity field determination

Autonomously working sensor platforms deliver an increasing amount of precise data sets, which are often usable in geodetic applications. Due to the volume and quality, models determined from the data can be parameterized more complex and in more detail. To derive model parameters from these observations, the solution of a high dimensional inverse data fitting problem is often required. To solve such high dimensional adjustment problems, this thesis proposes a systematical, end-to-end use of a massive parallel implementation of the geodetic data analysis, using standard concepts of massive parallel high performance computing. It is shown how these concepts can be integrated into a typical geodetic problem, which requires the solution of a high dimensional adjustment problem. Due to the proposed parallel use of the computing and memory resources of a compute cluster it is shown, how general Gauss-Markoff models become solvable, which were only solvable by means of computationally motivated simplifications and approximations before. A basic, easy-to-use framework is developed, which is able to perform all relevant operations needed to solve a typical geodetic least squares adjustment problem. It provides the interface to the standard concepts and libraries used. Examples, including different characteristics of the adjustment problem, show how the framework is used and can be adapted for specific applications. In a computational sense rigorous solutions become possible for hundreds of thousands to millions of unknown parameters, which have to be estimated from a huge number of observations. Three special problems with different characteristics, as they arise in global gravity field recovery, are chosen and massive parallel implementations of the solution processes are derived. The first application covers global gravity field determination from real data as collected by the GOCE satellite mission (comprising 440 million highly correlated observations, 80,000 parameters). Within the second application high dimensional global gravity field models are estimated from the combination of complementary data sets via the assembly and solution of full normal equations (scenarios with 520,000 parameters, 2 TB normal equations). The third application solves a comparable problem, but uses an iterative least squares solver, allowing for a parameter space of even higher dimension (now considering scenarios with two million parameters). This thesis forms the basis for a flexible massive parallel software package, which is extendable according to further current and future research topics studied in the department. Within this thesis, the main focus lies on the computational aspects.Autonom arbeitende Sensorplattformen liefern präzise geodätisch nutzbare Datensätze in größer werdendem Umfang. Deren Menge und Qualität führt dazu, dass Modelle die aus den Beobachtungen abgeleitet werden, immer komplexer und detailreicher angesetzt werden können. Zur Bestimmung von Modellparametern aus den Beobachtungen gilt es oftmals, ein hochdimensionales inverses Problem im Sinne der Ausgleichungsrechnung zu lösen. Innerhalb dieser Arbeit soll ein Beitrag dazu geleistet werden, Methoden und Konzepte aus dem Hochleistungsrechnen in der geodätischen Datenanalyse strukturiert, durchgängig und konsequent zu verwenden. Diese Arbeit zeigt, wie sich diese nutzen lassen, um geodätische Fragestellungen, die ein hochdimensionales Ausgleichungsproblem beinhalten, zu lösen. Durch die gemeinsame Nutzung der Rechen- und Speicherressourcen eines massiv parallelen Rechenclusters werden Gauss-Markoff Modelle lösbar, die ohne den Einsatz solcher Techniken vorher höchstens mit massiven Approximationen und Vereinfachungen lösbar waren. Ein entwickeltes Grundgerüst stellt die Schnittstelle zu den massiv parallelen Standards dar, die im Rahmen einer numerischen Lösung von typischen Ausgleichungsaufgaben benötigt werden. Konkrete Anwendungen mit unterschiedlichen Charakteristiken zeigen das detaillierte Vorgehen um das Grundgerüst zu verwenden und zu spezifizieren. Rechentechnisch strenge Lösungen sind so für Hunderttausende bis Millionen von unbekannten Parametern möglich, die aus einer Vielzahl von Beobachtungen geschätzt werden. Drei spezielle Anwendungen aus dem Bereich der globalen Bestimmung des Erdschwerefeldes werden vorgestellt und die Implementierungen für einen massiv parallelen Hochleistungsrechner abgeleitet. Die erste Anwendung beinhaltet die Bestimmung von Schwerefeldmodellen aus realen Beobachtungen der Satellitenmission GOCE (welche 440 Millionen korrelierte Beobachtungen umfasst, 80,000 Parameter). In der zweite Anwendung werden globale hochdimensionale Schwerefelder aus komplementären Daten über das Aufstellen und Lösen von vollen Normalgleichungen geschätzt (basierend auf Szenarien mit 520,000 Parametern, 2 TB Normalgleichungen). Die dritte Anwendung löst dasselbe Problem, jedoch über einen iterativen Löser, wodurch der Parameterraum noch einmal deutlich höher dimensional sein kann (betrachtet werden nun Szenarien mit 2 Millionen Parametern). Die Arbeit bildet die Grundlage für ein massiv paralleles Softwarepaket, welches schrittweise um Spezialisierungen, abhängig von aktuellen Forschungsprojekten in der Arbeitsgruppe, erweitert werden wird. Innerhalb dieser Arbeit liegt der Fokus rein auf den rechentechnischen Aspekten

Analiza poremećaja ubrzanja sile teže graničnih struktura na području Egejskog mora i Zapadne Anatolije

Western Anatolia has been shaped N–S-trending extensional tectonic regime and W-E trending horst, grabens and active faults due to the collision of Africa, Arabian and Eurasia plates. The borders of the Aegean Sea tectonic is limited between eastern of Greece, western of Anatolia and Hellenic subduction zone in the south of Crete. To evaluate these tectonic elements gravity disturbance data of the Aegean Sea and Western Anatolia was used in this study. It is thought that the gravity disturbance data reflects the tectonic elements and discontinuities way better than gravity anomaly due to the calculation from the difference between gravity and normal gravity at the same point so thus the tensors and invariants of the study area were calculated and the power spectrum method was applied to the gravity disturbance data. Various boundary analysis methods were applied to the gravity disturbance data to compare the discontinuities obtained from the tensors both theoretical and case study. These methods were tested initially on theoretical data. Within the scope of the theoretical study, a single model and three bodies model were taken into consideration. When the results are examined, it is observed that the Tzz tensor component gives very clear information about the location of the structure. Likewise, when the Txx, Tyy components and invariant results are examined, the vertical and horizontal boundaries were successfully obtained. In addition, the mean depths of these structures were determined using the power spectrum method. In the case application stage, the gravity disturbance data obtained from the Earth Gravitational Model of the eastern of the Aegean Sea and western of Anatolia were evaluated. The tensor and invariants of this gravity disturbance data were first calculated. New possible discontinuities have been identified in the tensors and some of the obtained discontinuities were clarified in their previous discussions. Also, the mean depths of the possible structures were calculated by the power spectrum method at four profiles taken from gravity disturbance data. These depth values are consistent with the depth values of the structural discontinuities obtained from previous studies. Finally, the upward continuation was applied to Tyy, Tyz and Tzz tensors up to 20 km. The positive anomaly values in Tyz and Tzz components and negative anomaly values in Tyy component are consistent with the Western Anatolia Transfer Zone. The structural differences between the eastern and the western of Western Anatolia are noteworthy in the upward continued results of the tensors. In addition, the positive and negative anomalies are notable in areas where the big earthquakes occurred in the last 3 years in the Tyz invariants.Zapadna Anatolija je oblikovana u smjeru sjever-jug zahvaljujući ekstenzivnom tektonskom trendu i zapadno-istočnim uzdizanjima, grebenima I aktivnim rasjedima kao posljedicom kolizije Afričke, Arapske i Euroazijske ploče. Granice tektonskog područja Egejskog mora ograničene su između istočne Grčke, zapadne Anatolije i Helenske subdukcijske zone na jugu Krete. Za procjenu tih tektonskih elemenata korišteni su podaci o poremećaju ubrzanja sile teže na području Egejskog mora i Zapadne Anatolije. Smatra se da podaci o poremećaju ubrzanja sile teže odražavaju tektonske elemente i diskontinuitete bolje nego anomalija ubrzanja sile teže zbog računanja razlike između ubrzanja sile teže i normalnog ubrzanja sile teže na istoj točki, tako da su izračunati tenzori i invarijante na promatranom području i metoda spektra snage je primijenjena na podatke poremećaja ubrzanja sile teže. Različite metode analize granica primijenjene su na podatke poremećaja ubrzanja sile teže kako bi se usporedili diskontinuiteti dobiveni iz tenzora. Te su metode najprije ispitane na teoretskim podacima. U okviru teorijske studije uzeti su u obzir jedan samostalni model i tri modela tijela. Prilikom interpretacije rezultata, uočeno je da Tzz tenzorska komponenta daje vrlo jasne informacije o lokaciji strukture. Isto tako, kada se ispitaju Txx, Tyy komponente i nepromjenjivi rezultati, uspješno su dobivene vertikalne i horizontalne granice. Također, srednje dubine tih struktura određene su metodom spektra snage. U stupnju primjene slučaja ispitani su podaci poremećaja ubrzanja sile teže generirani iz Zemljinog gravitacijskog modela EGM na području istočnog Egejskog mora i zapadne Anatolije. Najprije su izračunati tenzor i invarijante poremećaja ubrzanja sile teže. Identificirani su novi mogući diskontinuiteti u tenzorima, a neki od dobivenih diskontinuiteta razjašnjeni su u prethodnim raspravama. Također, prosječne dubine mogućih struktura izračunate su metodom spektra snage na četiri profila iz podataka o poremećaju ubrzanja sile teže. Ove dubinske vrijednosti su u skladu s dubinskim vrijednostima strukturnih diskontinuiteta dobivenih iz prethodnih studija. Naposljetku, kontinuacija prema gore primijenjen je na tenzore Tyy, Tyz i Tzz do 20 km. Vrijednosti pozitivnih anomalija u Tyz i Tzz komponentama i negativne vrijednosti anomalija u Tyy komponenti u skladu su sa transfer zonom Zapadne Anatolije. Strukturne razlike između istočnog i zapadnog dijela Zapadne Anatolije značajne su u daljnjim rezultatima tenzora. Također, pozitivne i negativne anomalije su značajne u područjima gdje su se dogodili veliki potresi u posljednje 3 godine u Tyz invarijantama