Geophysical Monitoring System Research Articles

The Kimberlina synthetic multiphysics dataset for CO2 monitoring investigations

AbstractWe present a synthetic multi‐scale, multi‐physics dataset constructed from the Kimberlina 1.2 CO2 reservoir model based on a potential CO2 storage site in the Southern San Joaquin Basin of California. Among 300 models, one selected reservoir‐simulation scenario produces hydrologic‐state models at the onset and after 20 years of CO2 injection. Subsequently, these models were transformed into geophysical properties, including P‐ and S‐wave seismic velocities, saturated density where the saturating fluid can be a combination of brine and supercritical CO2, and electrical resistivity using established empirical petrophysical relationships. From these 3D distributions of geophysical properties, we have generated synthetic time‐lapse seismic, gravity and electromagnetic responses with acquisition geometries that mimic realistic monitoring surveys and are achievable in actual field situations. We have also created a series of synthetic well logs of CO2 saturation, acoustic velocity, density and induction resistivity in the injection well and three monitoring wells. These were constructed by combining the low‐frequency trend of the geophysical models with the high‐frequency variations of actual well logs collected at the potential storage site. In addition, to better calibrate our datasets, measurements of permeability and pore connectivity have been made on cores of Vedder Sandstone, which forms the primary reservoir unit. These measurements provide the range of scales in the otherwise synthetic dataset to be as close to a real‐world situation as possible. This dataset consisting of the reservoir models, geophysical models, simulated time‐lapse geophysical responses and well logs forms a multi‐scale, multi‐physics testbed for designing and testing geophysical CO2 monitoring systems as well as for imaging and characterization algorithms. The suite of numerical models and data have been made publicly available for downloading on the National Energy Technology Laboratory's (NETL) Energy Data Exchange (EDX) website.

Analysis of Thermally Induced Strain Effects on a Jointed Rock Mass through Microseismic Monitoring at the Acuto Field Laboratory (Italy)

The study of the deformation of rock masses in response to near-surface thermal stresses is nowadays considered crucial in the field of geological risk mitigation. The superposition of heating and cooling cycles can influence the mechanical behavior of rock masses by inducing inelastic deformations that can trigger shallow slope instabilities, such as rockfalls and rock topples. This study reports the main outcomes obtained from the analysis of 20 month long microseismic monitoring at the Acuto field laboratory (Central Italy), where an integrated geotechnical and geophysical monitoring system has been operating since 2015. A preliminary event classification was performed through the analysis of time- and frequency-domain characteristic features of the extracted waveforms. Furthermore, the evolution of the local microseismicity was explored as a function of environmental factors (i.e., rock and air temperature, thermal gradients and ranges, and rainfalls) to highlight potential correlations. The here presented results highlight nontrivial insights into the role played by continuous near-surface temperature fluctuations and extreme thermal transients in influencing the stability of rock masses. In particular, the comparison of monitoring periods characterized by the most intense microseismic activity highlights a peculiar distribution of microseismicity during the heating and cooling phases of the rock mass in relation to different environmental conditions. These behaviors can be interpreted as the consequence of different driving mechanisms at the base of local failures.

Developing a novel geophysical tool to investigate the influence of vegetation on slope stability

Vegetation is important for managing shallow geotechnical assets. However, root water uptake-driven changes in slope hydrology and the near-surface (soil water content, matric suction, and hydraulic conductivity) are highly complex. Improved knowledge of these processes is increasingly important as society faces the threat of a greater prevalence of climate-driven extreme rainfall and drought events. Intrinsic factors affect slope stability, including geometry, soil properties, groundwater, and vegetation-driven matric suction. Field evidence shows that engineered slopes are susceptible to hydrometeorological instability mechanisms and pose a potential failure hazard to asset operation and public safety. This study considers the combination of a novel geophysical monitoring system and geotechnical point sensors for use in controlled laboratory conditions to assess the influence of vegetation on soil-water dynamics in the context of geotechnical infrastructure. The geophysical monitoring system, referred to here as PRIME (Proactive Infrastructure Monitoring and Evaluation system), uses electrical resistivity tomography (ERT) technology to non-invasively image changing subsurface moisture-driven processes. The PRIME system and point sensor arrays are being developed for near real-time data acquisition of transient soil moisture conditions in a suite of soil column experiments. Through addressing the challenges associated with designing integrated geophysical-geotechnical laboratory-scale monitoring experiments, this research aims to provide new tools and approaches to further our understanding of vegetation-driven soil moisture movement to better assess slope instability risk.

Relativistic gravimetry

Work on the creation of a device that will be able to measure the parameters of the Earth’s gravitational field in space was started at the State Design Office «Yuzhnoye» in 2001 as part of the formation of a scientific research program on the «Sich-1M» spacecraft. But since there were no devices in the world to directly measure the parameters of the Earth’s gravitational field in space, the idea arose to use the relativistic «red shift» effect to solve this problem. The possibility of practical implementation of this idea arose in 2008—2010 during the implementation of the STCU project No. 3856 «Measurement of the parameters of the Earth’s gravitational field using navigation satellite systems». Within the framework of this project, for the first time, a differential radiophysical gravimeter was created and tested, in which the radiation of navigation satellites was used as a source of highly stable radiation. Radiophysical method for measuring the parameters of the Earth’s gravitational field based on the results of dissertation research, 4 patents for an invention of Ukraine, 2 copyright certificates were obtained, and 16 articles were published in scientific journals. In 2012, the fundamental patent No. 98358 «Method for measuring geodetic parameters and a device for its implementation» was obtained, which was recognized in 2014 as the best patent of Ukraine in the absolute nomination in the competition «Best Patent of Ukraine». This patent formed the basis for the creation of the «Gravika» — navigation control and correction station. This work has been continued at JSC «RPC «KURS» since 2015. Since 2015, JSC «RPC «KURS» has been the head organization in the NSAU for the creation of a coordinate-clock and navigation support network for Ukraine. In 2016, it was created, certified and put into operation control and correction station (CCS) «Gravika», which can simultaneously operate both as a navigational base station and as a gravimeter, that is, to solve a complete geodetic problem. The principle of operation of the gravimeter is based on the relativistic effect of «red shift». One of the main technical and economic problems is the need to use a highly stable hydrogen frequency standard as part of the Gravika control and correction station, the cost of which is at least USD 80,000 (code «Geomonitoring») in order to develop a concept for creating, on the basis of the existing network of coordinate-clock and navigation support in Ukraine, a complex a clear geophysical monitoring system using the Gravika control and correction station and a satellite system for relaying signals of a highly stable TWSTFT frequency standard. Such a solution will make it possible to abandon the use of a frequency standard at each station and thereby reduce the cost of the CCS and the system as a whole. In addition, the work of the CCS «Gravika» showed the possibility of predicting seismic activity within a radius of 500 km from the station. A three-axis version of the gravimeter was also implemented, which allows you to simultaneously measure the absolute, relative values of the gravitational acceleration and the angle of inclination of the gravitational acceleration vector. Such functionality makes the radiophysical gravimeter indispensable when used on mobile vehicles, including space vehicles.

Integrated geodynamic studies of the Tien Shan lithosphere: state and prospects

The results of integrated geophysical studies of the Tien Shan lithosphere, including the territory of the Bishkek geodynamic test site (Northern Tien Shan), are considered. The characteristics of the main directions of fundamental research are given and the prospects for their further development are shown. The results obtained during the implementation of a number of large projects on the study of the deep structure of the Earth’s crust and the upper mantle of the Tien Shan by the method of magnetotelluric sounding are shown in order to identify the relationship of the near-surface structures of the Earth’s crust with deep structures and the deep geodynamic processes responsible for them. The main objects of research were the junction zones of the Pamir and Tien Shan, Tarim and Tien Shan, as well as a series of regional profiles and the territory of the Bishkek geodynamic test site. On this basis, the main regional features of the distribution of geoelectric inhomogeneities in the geological environment were determined and geophysical evidence of the existence of a zone of lateral plastic flow in the Earth’s crust under the Alai depression was obtained. To study catastrophic endogenous and exogenous processes, including the problems of forecasting and reducing the level of negative consequences, a system has been created with unique technical characteristics and a methodology for azimuthal magnetotelluric monitoring has been developed. The characteristics of research work on the creation of a system of complex geodynamic monitoring of the state of the Earth’s crust in the seismically active Tien Shan region are given. The results of the listed fundamental studies have been published in a large number of Russian and foreign research articles. The breadth of the topics of geophysical research carried out on the territory of the Bishkek geodynamic test site made it possible to obtain significant volumes of new scientific information. The priority directions of improvement and development of the integrated geophysical monitoring system are shown.

МЕТРОЛОГИЧЕСКОЕ ОБЕСПЕЧЕНИЕ ИОНОСФЕРНОЙ, МАГНИТНОЙ НАБЛЮДАТЕЛЬНОЙ СЕТИ РОСГИДРОМЕТА

The paper deals with the methods for metrological support of ionospheric, magnetic, and heliogeophysical observations of the state observation network, including ground-based and space segments, and with the directions for improving the accuracy and reliability of measurements. The solutions to the previously identified problems and the implementation of proposals on improving the measurement quality for operational response to heliogeophysical hazards at the current stage of development of the geophysical monitoring system are demonstrated.

Geophysical Monitoring of Moisture‐Induced Landslides: A Review

AbstractGeophysical monitoring of landslides can provide insights into spatial and temporal variations of subsurface properties associated with slope failure. Recent improvements in equipment, data analysis, and field operations have led to a significant increase in the use of such techniques in monitoring. Geophysical methods complement intrusive approaches, which sample only a very small proportion of the subsurface, and walk‐over or remotely sensed data, which principally provide information only at the ground surface. In particular, recent studies show that advances in geophysical instrumentation, data processing, modeling, and interpretation in the context of landslide monitoring are significantly improving the characterization of hillslope hydrology and soil and rock hydrology and strength and their dynamics over time. This review appraises the state of the art of geophysical monitoring, as applied to moisture‐induced landslides. Here we focus on technical and practical uses of time‐lapse methods in geophysics applied to monitoring moisture‐induced landslide. The case studies identified in this review show that several geophysical techniques are currently used in the monitoring of subsurface landslide processes. These geophysical contributions to monitoring and predicting the evolution of landslide processes are currently underrealized. Hence, the further integration of multiple‐parametric and geotechnically coupled geophysical monitoring systems has considerable potential. The complementary nature of certain methods to map the distribution of subsurface moisture and elastic moduli will greatly increase the predictive and monitoring capacity of early warning systems in moisture‐induced landslide settings.

Development of the space observation system and geophysical monitoring system in Roshydromet

Two important areas of Roshydromet activity are considered: the development of the space observation system and the creation of the system of ground-, air-, and space-based geophysical monitoring. The investigation, monitoring, and forecasting of the state of the Earth, its climate, severe weather events, catastrophes, and emergencies requires the extended usage of space observation methods. The current state is considered of hydrometeorological space system included in the Roshydromet space observation system. The space- and ground-based segments of this system are briefly described. The ground segment is based on the national space monitoring system which was developed in 1992—2010 and is geographically distributed. The works are reviewed on the formation of the Roshydromet geophysical monitoring system using ground-based, airborne, and space-based observations.

The unrest of the San Miguel volcano (El Salvador, Central America): installation of the monitoring network and observed volcano-tectonic ground deformation

Abstract. On 29 December 2013, the Chaparrastique volcano in El Salvador, close to the town of San Miguel, erupted suddenly with explosive force, forming a column more than 9 km high and projecting ballistic projectiles as far as 3 km away. Pyroclastic density currents flowed to the north-northwest side of the volcano, while tephras were dispersed northwest and north-northeast. This sudden eruption prompted the local Ministry of Environment to request cooperation with Italian scientists in order to improve the monitoring of the volcano during this unrest. A joint force, made up of an Italian team from the Istituto Nazionale di Geofisica e Vulcanologia and a local team from the Ministerio de Medio Ambiente y Recursos Naturales, was organized to enhance the volcanological, geophysical and geochemical monitoring system to study the evolution of the phenomenon during the crisis. The joint team quickly installed a multiparametric mobile network comprising seismic, geodetic and geochemical sensors (designed to cover all the volcano flanks from the lowest to the highest possible altitudes) and a thermal camera. To simplify the logistics for a rapid installation and for security reasons, some sensors were colocated into multiparametric stations. Here, we describe the prompt design and installation of the geodetic monitoring network, the processing and results. The installation of a new ground deformation network can be considered an important result by itself, while the detection of some crucial deforming areas is very significant information, useful for dealing with future threats and for further studies on this poorly monitored volcano.

EXPERIENCE OF COMPLEXATION OF GLOBAL GEOPHYSICAL OBSERVATIONS

The technique of joint analysis of heterogeneous time series of geophysical monitoring systems for the purpose of detecting time intervals and specific periods of bursts of synchronous behavior is presented. The technique is based on the use of the Fourier‐aggregated signals and spectral measures of coherent behavior of multivariate time series, estimated in moving time windows. The article presents results of the analysis of data of underground electrical surveys at stations located in Kamchatka, Altai and Italy; the data were analysed together with torsion pendulum movements in Tula (Russia) and the time series of seismic noise parameters at the Japanese islands for the interval 2012–2015. The analysis identified a number of significant bursts of coherent behavior for these observations, some of which are presumably due to the strong mantle Okhotsk Sea earthquake of 24 May 2013. The coherent behavior of various geophysical fields before and after strong earthquakes is interpreted as a manifestation of the general pattern of increasing synchronization of fluctuations of complex systems at their approach to the rapid changes in their properties.

다용도 실시간 경사각과 방위각 연속 측정 시스템 개발연구

최근 지구물리 물리탐사 분야에서 경사각과 방위각 정보는 시추공 물리검층 및 물리탐사 자료보정을 위한 시추공 편차검층, 이동형 실시간 자료획득 시스템, 기타 지구물리 모니터링 시스템 등 다양하게 활용되면서 그 중요성이 높아지고 있다. 특히 최근 셰일가스의 개발이 가능하게 한 방향시추 기술에서도 경사각과 방위각 정보는 필수일 정도로 그 응용범위가 매우 넓다. 따라서 여러 분야에 응용될 수 있는 경사각과 방위각 측정 시스템의 초소형 옥외 저전력 운용이 절실해졌다. 본 논문에서는 최신 CMOS 저전력, 고성능 MCU 및 멤스(MEMS) 자세방위기준장치(AHRS)를 도입하여 초소형, 저전력으로 제작된 다용도 야외시험용 실시간 경사각과 방위각 연속 측정 시스템 개발 연구의 결과를 제시하고자 한다. 시스템은 최소 지름 42 mm의 존데 내에 설치될 수 있도록 초슬림 형태로 제작되었으며 실시간 데이터 획득이 가능할 뿐만 아니라 엔코더, DGPS 연동으로 운용 확장이 가능하여 다양한 응용이 기대된다. In geophysics and geophysical exploration fields, we can use information about inclination and azimuth in various ways. These include borehole deviation logging for inversion process, real-time data acquisition system, geophysical monitoring system, and so on. This type of information is also necessarily used in the directional drilling of shale gas fields. We thus need to develop a subminiature, low-powered, multi-functional inclination and azimuth measurement system for geophysical exploration fields. In this paper, to develop real-time measurement system, we adopt the high performance low power Micro Control Unit (made with state-of-the-art Complementary Metal Oxide Semiconductor technology) and newly released Micro Electro Mechanical Systems Attitude Heading Reference System sensors. We present test results on the development of a multifunctional real-time inclination and azimuth measurement system. The developed system has an ultra-slim body so as to be installed in 42mm sonde. Also, this system allows us to acquire data in real-time and to easily expand its application by synchronizing with a depth encoder or Differential Global Positioning System.

Specialized seismic noise registration station “Nachiki” in the geophysical monitoring system of Kamchatka

The specialized station of high-frequency seismic noise registration “Nachiki” is described arranged on Kamchatka in 1987. The instrument-methodical aspects of registration are considered, as well as history of observations development. New principal experimental results of surveys are represented. The results of use of high-frequency seismic noises are summarized to reveal strong earthquake precursors in the online mode in 1996–2008.

Geodetic monitoring of Mt. Vesuvius Volcano, Italy, based on EDM and GPS surveys

The geophysical monitoring system of Mt. Vesuvius volcano includes a geodetic EDM network having average basis lengths amounting to 6 km. This trilateration network is localised around the central crater and consists of 21 stations with a geometry allowing measurement of 60 slope distances. In order to relate this network to more stable areas and to other networks in the Apennines, the EDM net has been extended using GPS methods. In summer 1993 four GPS receivers (Leica System 200) were used on the same points measured with EDM method. During this survey two long bases from the volcano to the more stable limestone platform located in the S direction were measured. The same baselines were previously measured by using an AGA 600 laser geodimeter. In January 1995 a new survey was performed by using two infrared distantiometers (1 DISTOMAT DI3000 and an AGA 142). The comparison with the data since 1975 does not show any significant ground deformation to be ascribed to the volcanic activity. Moreover the consistency between GPS and EDM data allows to exclude systematic differences between these two methodologies for volcano monitoring.

Energy absorbed in solid thin layers

The geophysical monitoring system of Mt. Vesuvius volcano includes a geodetic EDM network having average basis lengths amounting to 6 km. This trilateration network is localised around the central crater and consists of 21 stations with a geometry allowing measurement of 60 slope distances. In order to relate this network to more stable areas and to other networks in the Apennines, the EDM net has been extended using GPS methods. In summer 1993 four GPS receivers (Leica System 200) were used on the same points measured with EDM method. During this survey two long bases from the volcano to the more stable limestone platform located in the S direction were measured. The same baselines were previously measured by using an AGA 600 laser geodimeter. In January 1995 a new survey was performed by using two infrared distantiometers (1 DISTOMAT DI3000 and an AGA 142). The comparison with the data since 1975 does not show any significant ground deformation to be ascribed to the volcanic activity. Moreover the consistency between GPS and EDM data allows to exclude systematic differences between these two methodologies for volcano monitoring.

The velocity of light

The geophysical monitoring system of Mt. Vesuvius volcano includes a geodetic EDM network having average basis lengths amounting to 6 km. This trilateration network is localised around the central crater and consists of 21 stations with a geometry allowing measurement of 60 slope distances. In order to relate this network to more stable areas and to other networks in the Apennines, the EDM net has been extended using GPS methods. In summer 1993 four GPS receivers (Leica System 200) were used on the same points measured with EDM method. During this survey two long bases from the volcano to the more stable limestone platform located in the S direction were measured. The same baselines were previously measured by using an AGA 600 laser geodimeter. In January 1995 a new survey was performed by using two infrared distantiometers (1 DISTOMAT DI3000 and an AGA 142). The comparison with the data since 1975 does not show any significant ground deformation to be ascribed to the volcanic activity. Moreover the consistency between GPS and EDM data allows to exclude systematic differences between these two methodologies for volcano monitoring.