Potential of megathrust earthquakes along the southern Ryukyu Trench inferred from GNSS data

AbstractThe southern part of the Ryukyu subduction zone has recorded tsunami events with a recurrence interval of several hundred years. Although their source is controversial, one model suggests that the last 1771 Yaeyama tsunami was caused by a shallow megathrust earthquake with a magnitude of 8. However, the current knowledge on interplate coupling based on recent geodetic data is limited. Here, a time series of Global Navigation Satellite System data from January 2010 to February 2021 was analyzed, including newly installed stations by Kyoto and Kyushu Universities, to obtain the distance changes between stations and vertical secular velocities. The distance changes ranged from 2.4 mm/year in contraction and to 4.7 mm/year in extension, and the vertical velocities exhibited no clear uplift or subsidence, with − 2.4 to 1.1 mm/year. The back slip inversion results indicated a slip deficit of 17–47 mm/year to the south of the Yaeyama Islands. The large slip deficit area is complementarily intervened between the shallower source area of low-frequency earthquakes and the deeper slow slip region, suggesting the spatial heterogeneity of frictional properties along the plate interface. If the large slip deficit area accumulates stress in the same rate since the last 1771 earthquake, it could result in a megathrust event with a moment magnitude greater than 7.5. Because the limited onshore data cannot resolve the slip deficit on the shallow plate interface, seafloor geodetic observations are essential to clarify the detailed spatial distribution of the slip deficit and discuss its earthquake and tsunami potential. Graphical Abstract

Download Full-text

Potential of Megathrust Earthquakes Along the Southern Ryukyu Trench Inferred from GNSS Data

10.21203/rs.3.rs-779185/v1 ◽

2021 ◽

Author(s):

Masayuki Kano ◽

Aoi Ikeuchi ◽

Takuya Nishimura ◽

Shin'ichi Miyazaki ◽

Takeshi Matsushima

Keyword(s):

Current Knowledge ◽

Low Frequency ◽

Source Area ◽

Satellite System ◽

Plate Interface ◽

Megathrust Earthquakes ◽

Slip Deficit ◽

Slip Region ◽

System Data ◽

Global Navigation Satellite

Abstract The southern part of the Ryukyu subduction zone has recorded tsunami events with a recurrence interval of several hundred years. Although their source is controversial, one model suggested that the last 1771 Yaeyama tsunami was caused by a shallow megathrust earthquake with a magnitude of 8. However, the current knowledge on interplate coupling based on recent geodetic data is limited. This study analyzed a time series of Global Navigation Satellite System data from January 2010 to February 2021, including newly installed stations by Kyoto and Kyushu Universities to obtain the distance changes between stations and vertical secular velocities. The distance changes ranged 2.4 mm/yr in contraction and 4.7 mm/yr in extension, and the vertical velocities exhibited no clear uplift or subsidence of -2.4 to 1.1 mm/yr. The back slip inversion results indicated the slip deficit of 16–54 mm/yr in the south of the Yaeyama Islands. The large slip deficit area is complementarily intervened between the shallower source area of low-frequency earthquakes and the deeper slow slip region, suggesting the spatial heterogeneity of frictional properties along the plate interface. If the large slip deficit area accumulates stress in the same rate since the last 1771 earthquake, it could result in a megathrust event of at least greater than a moment magnitude of 7.7. Because the limited onshore data cannot resolve the slip deficit on the shallow plate interface, seafloor geodetic observations are essential to clarify the detailed spatial distribution of slip deficit and discuss its earthquake and tsunami potential.

Download Full-text

Fused inertial measurement unit and real time kinematic-global navigation satellite system data assessment based on robotic total station information for in-field dynamic positioning

Precision agriculture '15 ◽

10.3920/978-90-8686-814-8_33 ◽

2015 ◽

pp. 275-282 ◽

Cited By ~ 2

Author(s):

D.S. Paraforos ◽

H.W. Griepentrog ◽

J. Geipel ◽

T. Stehle

Keyword(s):

Satellite System ◽

Measurement Unit ◽

Dynamic Positioning ◽

Navigation Satellite ◽

Inertial Measurement ◽

Data Assessment ◽

Field Dynamic ◽

System Data ◽

Global Navigation Satellite ◽

Robotic Total Station

Download Full-text

Can we detect X/M/C-class solar flares from global navigation satellite system data?

Results in Physics ◽

10.1016/j.rinp.2018.12.069 ◽

2019 ◽

Vol 12 ◽

pp. 1004-1005 ◽

Cited By ~ 2

Author(s):

Semen V. Syrovatskiy ◽

Yury V. Yasyukevich ◽

Ilya K. Edemskiy ◽

Artem M. Vesnin ◽

Sergey V. Voeykov ◽

...

Keyword(s):

Global Navigation Satellite System ◽

Solar Flares ◽

Satellite System ◽

Navigation Satellite ◽

System Data ◽

Global Navigation ◽

Global Navigation Satellite

Download Full-text

Derivation of global ionospheric Sporadic E critical frequency ( f o Es) data from the amplitude variations in GPS/GNSS radio occultations

Royal Society Open Science ◽

10.1098/rsos.200320 ◽

2020 ◽

Vol 7 (7) ◽

pp. 200320 ◽

Cited By ~ 1

Author(s):

Bingkun Yu ◽

Christopher J. Scott ◽

Xianghui Xue ◽

Xinan Yue ◽

Xiankang Dou

Keyword(s):

Critical Frequency ◽

Detection Threshold ◽

Low Frequency ◽

Satellite System ◽

Global Scale ◽

Satellite Mission ◽

Frequency Detection ◽

Sporadic E ◽

The Uk ◽

Global Navigation Satellite

The ionospheric sporadic E (Es) layer has a significant impact on the global positioning system (GPS)/global navigation satellite system (GNSS) signals. These influences on the GPS/GNSS signals can also be used to study the occurrence and characteristics of the Es layer on a global scale. In this paper, 5.8 million radio occultation (RO) profiles from the FORMOSAT-3/COSMIC satellite mission and ground-based observations of Es layers recorded by 25 ionospheric monitoring stations and held at the UK Solar System Data Centre at the Rutherford Appleton Laboratory and the Chinese Meridian Project were used to derive the hourly Es critical frequency ( f o Es) data. The global distribution of f o Es with a high spatial resolution shows a strong seasonal variation in f o Es with a summer maximum exceeding 4.0 MHz and a winter minimum between 2.0 and 2.5 MHz. The GPS/GNSS RO technique is an important tool that can provide global estimates of Es layers, augmenting the limited coverage and low-frequency detection threshold of ground-based instruments. Attention should be paid to small f o Es values from ionosondes near the instrumental detection limits corresponding to minimum frequencies in the range 1.28–1.60 MHz.

Download Full-text

Rupture kinematics of 2020 January 24 Mw 6.7 Doğanyol-Sivrice, Turkey earthquake on the East Anatolian Fault Zone imaged by space geodesy

Geophysical Journal International ◽

10.1093/gji/ggaa345 ◽

2020 ◽

Vol 223 (2) ◽

pp. 862-874 ◽

Cited By ~ 6

Author(s):

Diego Melgar ◽

Athanassios Ganas ◽

Tuncay Taymaz ◽

Sotiris Valkaniotis ◽

Brendan W Crowell ◽

...

Keyword(s):

Fault Zone ◽

Satellite System ◽

High Rate ◽

Slip Model ◽

Slip Region ◽

Global Navigation Satellite ◽

Rupture Kinematics ◽

Source Duration ◽

East Anatolian Fault Zone ◽

East Anatolian Fault

SUMMARY Here, we present the results of a kinematic slip model of the 2020 Mw 6.7 Doğanyol-Sivrice, Turkey Earthquake, the most important event in the last 50 yr on the East Anatolian Fault Zone. Our slip model is constrained by two Sentinel-1 interferograms and by 5 three-component high-rate GNSS (Global Navigation Satellite System) recordings close to the earthquake source. We find that most of the slip occurs predominantly in three regions, two of them at between 2 and 10 km depth and a deeper slip region extending down to 20 km depth. We also relocate the first two weeks of aftershocks and find a distribution of events that agrees with these slip features. The HR-GNSS recordings suggest a predominantly unilateral rupture with the effects of a directivity pulse clearly seen in the waveforms and in the measure peak ground velocities. The slip model supports rupture propagation from northeast to southwest at a relatively slow speed of 2.2 km s−1 and a total source duration of ∼20 s. In the absence of near-source seismic stations, space geodetic data provide the best constraint on the spatial distribution of slip and on its time evolution.

Download Full-text

Estimation of Wave Characteristics Based on Global Navigation Satellite System Data Installed on Board Sailboats

Sensors ◽

10.3390/s19102295 ◽

2019 ◽

Vol 19 (10) ◽

pp. 2295

Author(s):

Paolo De Girolamo ◽

Mattia Crespi ◽

Alessandro Romano ◽

Augusto Mazzoni ◽

Marcello Di Risio ◽

...

Keyword(s):

Satellite System ◽

Western Mediterranean ◽

Real Time Control ◽

Western Mediterranean Sea ◽

Time Control ◽

Self Sufficiency ◽

Local Wave ◽

System Data ◽

Global Navigation Satellite ◽

Wave Properties

This paper illustrates a methodology to get a reliable estimation of the local wave properties, based on the reconstruction of the motion of a moving sailboat by means of GNSS receivers installed on board and an original kinematic positioning approach. The wave parameters reconstruction may be used for many useful practical purposes, e.g., to improve of autopilots, for real-time control systems of ships, to analyze and improve the performance of race sailboats, and to estimate the local properties of the waves. A Class 40 oceanic vessel (ECO40) left from the port of “Riva di Traiano” located close to Rome (Italy) on 19 October 2014 to perform a non-stop sailing alone around the world in energy and food self-sufficiency. The proposed system was installed on ECO40 and the proposed method was applied to estimate the wave properties during a storm in the Western Mediterranean Sea. The results compared against two sets of hindcast data and wave buoy records demonstrated the reliability of the method.

Download Full-text

GNSS/INS-Equipped Buoys for Altimetry Validation: Lessons Learnt and New Directions from the Bass Strait Validation Facility

Remote Sensing ◽

10.3390/rs12183001 ◽

2020 ◽

Vol 12 (18) ◽

pp. 3001

Author(s):

Boye Zhou ◽

Christopher Watson ◽

Benoit Legresy ◽

Matt A. King ◽

Jack Beardsley ◽

...

Keyword(s):

Inertial Navigation System ◽

Low Frequency ◽

Satellite System ◽

External Forcing ◽

Empirical Correction ◽

New Directions ◽

Ocean Topography ◽

Global Navigation Satellite ◽

Systematic Noise

Global Navigation Satellite System (GNSS)-equipped buoys have a fundamental role in the validation of satellite altimetry. Requirements to validate next generation altimeter missions are demanding and call for a greater understanding of the systematic errors associated with the buoy approach. In this paper, we assess the present-day buoy precision using archived data from the Bass Strait validation facility. We explore potential improvements in buoy precision by addressing two previously ignored issues: changes to buoyancy as a function of external forcing, and biases induced by platform dynamics. Our results indicate the precision of our buoy against in situ mooring data is ~15 mm, with a ~8.5 mm systematic noise floor. Investigation into the tether tension effect on buoyancy showed strong correlation between currents, wind stress and buoy-against-mooring residuals. Our initial empirical correction achieved a reduction of 5 mm in the standard deviation of the residuals, with a 51% decrease in variance over low frequency bands. Corrections associated with platform orientation from an Inertial Navigation System (INS) unit showed centimetre-level magnitude and are expected to be higher under rougher sea states. Finally, we conclude with further possible improvements to meet validation requirements for the future Surface Water Ocean Topography (SWOT) mission.

Download Full-text

Subsidence determination in the Central Valley, California

Reports on Geodesy and Geoinformatics ◽

10.2478/rgg-2018-0012 ◽

2018 ◽

Vol 106 (1) ◽

pp. 35-42 ◽

Cited By ~ 1

Author(s):

Marcelo Romero ◽

Mike Mustafa Berber

Keyword(s):

Central Valley ◽

Satellite System ◽

Geodetic Survey ◽

Reference Station ◽

National Geodetic Survey ◽

The North ◽

Elevation Changes ◽

System Data ◽

Global Navigation Satellite ◽

Gnss Data

Abstract Twenty four hour GNSS (Global Navigation Satellite System) data acquired monthly for 5 years from 8 CORS (Continuously Operating Reference Station) stations in Central Valley, California are processed and vertical velocities of the points are determined. To process GNSS data, online GNSS data processing service APPS (Automatic Precise Positioning Service) is used. GNSS data downloaded from NGS (National Geodetic Survey) CORS are analyzed and subsidence at these points is portrayed with graphics. It is revealed that elevation changes range from 5 mm uplift in the north to 163 mm subsidence in the southern part of the valley.

Download Full-text

The 2018–2019 seismo-volcanic crisis east of Mayotte, Comoros islands: seismicity and ground deformation markers of an exceptional submarine eruption

Geophysical Journal International ◽

10.1093/gji/ggaa273 ◽

2020 ◽

Vol 223 (1) ◽

pp. 22-44 ◽

Cited By ~ 5

Author(s):

Anne Lemoine ◽

Pierre Briole ◽

Didier Bertil ◽

Agathe Roullé ◽

Michael Foumelis ◽

...

Keyword(s):

Ground Deformation ◽

Low Frequency ◽

Harmonic Oscillation ◽

Satellite System ◽

First Year ◽

Secondary Source ◽

Magma Intrusion ◽

Volcanic Event ◽

Volcanic Islands ◽

Global Navigation Satellite

SUMMARY On 10 May 2018, an unprecedented long and intense seismic crisis started offshore, east of Mayotte, the easternmost of the Comoros volcanic islands. The population felt hundreds of events. Over the course of 1 yr, 32 earthquakes with magnitude greater than 5 occurred, including the largest event ever recorded in the Comoros (Mw = 5.9 on 15 May 2018). Earthquakes are clustered in space and time. Unusual intense long lasting monochromatic very long period events were also registered. From early July 2018, Global Navigation Satellite System (GNSS) stations and Interferometric Synthetic Aperture Radar (InSAR) registered a large drift, testimony of a large offshore deflation. We describe the onset and the evolution of a large magmatic event thanks to the analysis of the seismicity from the initiation of the crisis through its first year, compared to the ground deformation observation (GNSS and InSAR) and modelling. We discriminate and characterize the initial fracturing phase, the phase of magma intrusion and dyke propagation from depth to the subsurface, and the eruptive phase that starts on 3 July 2018, around 50 d after the first seismic events. The eruption is not terminated 2 yr after its initiation, with the persistence of an unusual seismicity, whose pattern has been similar since summer 2018, including episodic very low frequency events presenting a harmonic oscillation with a period of ∼16 s. From July 2018, the whole Mayotte Island drifted eastward and downward at a slightly increasing rate until reaching a peak in late 2018. At the apex, the mean deformation rate was 224 mm yr−1 eastward and 186 mm yr−1 downward. During 2019, the deformation smoothly decreased and in January 2020, it was less than 20 per cent of its peak value. A deflation model of a magma reservoir buried in a homogenous half space fits well the data. The modelled reservoir is located 45 ± 5 km east of Mayotte, at a depth of 28 ± 3 km and the inferred magma extraction at the apex was ∼94 m3 s−1. The introduction of a small secondary source located beneath Mayotte Island at the same depth as the main one improves the fit by 20 per cent. While the rate of the main source drops by a factor of 5 during 2019, the rate of the secondary source remains stable. This might be a clue of the occurrence of relaxation at depth that may continue for some time after the end of the eruption. According to our model, the total volume extracted from the deep reservoir was ∼2.65 km3 in January 2020. This is the largest offshore volcanic event ever quantitatively documented. This seismo-volcanic crisis is consistent with the trans-tensional regime along Comoros archipelago.

Download Full-text