scholarly journals Geodetic, hydrologic and seismological signals associated with precipitation and infiltration in the central Southern Alps, New Zealand

2021 ◽  
Author(s):  
◽  
Nicolas Oestreicher
Keyword(s):  
New Zealand ◽  
Surface Deformation ◽  
Ground Deformation ◽  
Ground Surface ◽  
Southern Alps ◽  
Hydrologic Cycle ◽  
Geodetic Data ◽  
Surface Processes ◽  
Groundwater Levels ◽  
Seismicity Rates

<p>The Southern Alps of New Zealand is an actively deforming mountain range, along which collision between the Pacific and Australian plates is manifest as elevated topography, orographic weather, active contemporary deformation, and earthquakes. This thesis examines interactions between surface processes of meteorological and hydrological origin, the ground surface deformation, and processes within the seismogenic zone at depth. The two main objectives of the thesis are a better understanding of the reversible repetitive ground surface deformation in the central Southern Alps and the analysis of the evolution of the rate of microseismicity in the area to explore relationships between seismicity rates and the hydrologic cycle.  Surface deformation in the central Southern Alps is characterised by a network of 19 continuous GPS stations located between the West Coast (west) and the Mackenzie Basin (east), and between Hokitika (north) to Haast (south). These show repetitive and reversible movements of up to ∼55mm on annual scales, on top of long-term plate motion, during a 17 year-long period. Stations in the high central Southern Alps exhibit the greatest annual variations, whereas others are more sensitive to changes following significant rain events. Data from 22 climate stations (including three measuring the snowpack), lake water levels and borehole pressure measurements, and numerical models of solid Earth tides and groundwater levels in bedrock fractures, are compared against geodetic data to examine whether these environmental factors can explain observed patterns in annual ground deformation. Reversible ground deformation in the central Southern Alps appears strongly correlated with shallow groundwater levels. Observed seasonal fluctuation and deformation after storm events can be explained by simple mathematical models of groundwater levels. As a corollary, local hydrological effects can be accounted for and ameliorated during preprocessing to reduce noise in geodetic data sets being analysed for tectonic purposes.  Two catalogues of earthquakes (containing 38 909 and 89 474 events) in the area spanning the period 2008–2017 were built using a matched-filtered detection technique. The smaller catalogue is based on 211 template events, each of known focal mechanism, while the latter is based on 902 templates, not all of which have focal mechanisms, providing greater temporal resolution. Microseismicity data were examined in both time and frequency domains to explore relationships between seismicity rates and the hydrologic cycle. Microseismicity shows a pronounced seasonality in the central Southern Alps, with significantly more events detected during winter than during summer. These changes cannot be easily accounted for by either acquisition or analysis parameters. Two models of hydrologically-induced seasonal seismicity variations have been considered — surface water loading and deep groundwater circulation of meteoric fluids — but neither model fully explains the observations, and further work is required to explain them fully. An observed diurnal variation in earthquake detection rate is believed to originate mostly from instrumental effects, which should be accounted for in future seismological studies of earthquake occurrence in the central Southern Alps.  Relationships and correlations observed between hydrological, geodetic, and seismological data from the central Southern Alps provide clear indications that surface processes exert at least some degree of influence on upper-crustal seismicity adjacent to the Alpine Fault.</p>

scholarly journals Geodetic, hydrologic and seismological signals associated with precipitation and infiltration in the central Southern Alps, New Zealand

2021 ◽  
Author(s):  
◽  
Nicolas Oestreicher
Keyword(s):  
New Zealand ◽  
Surface Deformation ◽  
Ground Deformation ◽  
Ground Surface ◽  
Southern Alps ◽  
Hydrologic Cycle ◽  
Geodetic Data ◽  
Surface Processes ◽  
Groundwater Levels ◽  
Seismicity Rates

<p>The Southern Alps of New Zealand is an actively deforming mountain range, along which collision between the Pacific and Australian plates is manifest as elevated topography, orographic weather, active contemporary deformation, and earthquakes. This thesis examines interactions between surface processes of meteorological and hydrological origin, the ground surface deformation, and processes within the seismogenic zone at depth. The two main objectives of the thesis are a better understanding of the reversible repetitive ground surface deformation in the central Southern Alps and the analysis of the evolution of the rate of microseismicity in the area to explore relationships between seismicity rates and the hydrologic cycle.  Surface deformation in the central Southern Alps is characterised by a network of 19 continuous GPS stations located between the West Coast (west) and the Mackenzie Basin (east), and between Hokitika (north) to Haast (south). These show repetitive and reversible movements of up to ∼55mm on annual scales, on top of long-term plate motion, during a 17 year-long period. Stations in the high central Southern Alps exhibit the greatest annual variations, whereas others are more sensitive to changes following significant rain events. Data from 22 climate stations (including three measuring the snowpack), lake water levels and borehole pressure measurements, and numerical models of solid Earth tides and groundwater levels in bedrock fractures, are compared against geodetic data to examine whether these environmental factors can explain observed patterns in annual ground deformation. Reversible ground deformation in the central Southern Alps appears strongly correlated with shallow groundwater levels. Observed seasonal fluctuation and deformation after storm events can be explained by simple mathematical models of groundwater levels. As a corollary, local hydrological effects can be accounted for and ameliorated during preprocessing to reduce noise in geodetic data sets being analysed for tectonic purposes.  Two catalogues of earthquakes (containing 38 909 and 89 474 events) in the area spanning the period 2008–2017 were built using a matched-filtered detection technique. The smaller catalogue is based on 211 template events, each of known focal mechanism, while the latter is based on 902 templates, not all of which have focal mechanisms, providing greater temporal resolution. Microseismicity data were examined in both time and frequency domains to explore relationships between seismicity rates and the hydrologic cycle. Microseismicity shows a pronounced seasonality in the central Southern Alps, with significantly more events detected during winter than during summer. These changes cannot be easily accounted for by either acquisition or analysis parameters. Two models of hydrologically-induced seasonal seismicity variations have been considered — surface water loading and deep groundwater circulation of meteoric fluids — but neither model fully explains the observations, and further work is required to explain them fully. An observed diurnal variation in earthquake detection rate is believed to originate mostly from instrumental effects, which should be accounted for in future seismological studies of earthquake occurrence in the central Southern Alps.  Relationships and correlations observed between hydrological, geodetic, and seismological data from the central Southern Alps provide clear indications that surface processes exert at least some degree of influence on upper-crustal seismicity adjacent to the Alpine Fault.</p>

Detecting land deformation due to groundwater changes with InSAR observations - the case of the island of Gotland, Sweden

2021 ◽  
Author(s):  
Mehdi Darvishi ◽  
Fernando Jaramillo
Keyword(s):  
Land Subsidence ◽  
Groundwater Level ◽  
Ground Deformation ◽  
Soil Depth ◽  
Ground Surface ◽  
Groundwater Depletion ◽  
Groundwater Levels ◽  
Small Baseline Subset ◽  
Small Baseline ◽  
The Baltic

&lt;p&gt;In the recent years, southern Sweden has experienced drought conditions during the summer with potential risks of groundwater shortages. One of the main physical effects of groundwater depletion is land subsidence, a geohazard that potentially damages urban infrastructure, natural resources and can generate casualties. We here investigate land subsidence induced by groundwater depletion and/or seasonal variations in Gotland, an agricultural island in the Baltic Sea experiencing recent hydrological droughts in the summer. Taking advantage of the multiple monitoring groundwater wells active on the island, we explore the existence of a relationship between groundwater fluctuations and ground deformation, as obtained from Interferometric Synthetic Aperture Radar (InSAR). The aim in the long-term is to develop a high-accuracy map of land subsidence with an appropriate temporal and spatial resolution to understand groundwater changes in the area are recognize hydroclimatic and anthropogenic drivers of change.&lt;/p&gt;&lt;p&gt;We processed Sentinel-1 (S1) data, covering the time span of 2016-2019, by using the Small BAseline Subset (SBAS) to process 119 S1-A/B data (descending mode). The groundwater level of Nineteen wells distributed over the Gotland island were used to assess the relationship between groundwater depletion and the detected InSAR displacement. In addition to that, the roles of other geological key factors such as soil depth, ground capacity in bed rock, karstification, structure of bedrock and soil type in occurring land subsidence also investigated. The findings showed that the groundwater level in thirteen wells with soil depths of less than 5 meters correlated well with InSAR displacements. The closeness of bedrock to ground surface (small soil depth) was responsible for high coherence values near the wells, and enabled the detection land subsidence. The results demonstrated that InSAR could use as an effective monitoring system for groundwater management and can assist in predicting or estimating low groundwater levels during summer conditions.&lt;/p&gt;

3D Visual Technology of Geo-Deformation Disasters Induced by Mining Subsidence Based on ArcGIS Engine

2012 ◽  
Vol 500 ◽  
pp. 428-436 ◽  
Author(s):  
Ke Ming Yang ◽  
Jun Ting Ma ◽  
Bo Pang ◽  
Yi Bin Wang ◽  
Ran Wang ◽  
...  
Keyword(s):  
Coal Mining ◽  
Surface Deformation ◽  
Ground Deformation ◽  
Ground Surface ◽  
Horizontal Displacement ◽  
Mining Subsidence ◽  
Underground Coal Mining ◽  
Vertical Movements ◽  
Probability Integral Method ◽  
Arcgis Engine

Mining subsidence often produces significant horizontal and vertical movements at the ground surface, the surface deformation induced by underground coal mining can be predicted by probability integral method, and the surface geo-deformation disasters can be visualized based on GIS components. A three dimensional (3D) visualizing system of surface geo-deformation information is designed and developed with ArcGIS Engine and C# in the study. According to the surface deformation-predicted data induced by underground coal mining in Guobei Coalmine of Huaibei mine field, the extents and degrees of ground deformation disasters are visualized in 3D views for surface vertical subsidence, slope, curvature, horizontal displacement and horizontal strain based on the GIS-developed application platform.

Monitoring Slope Deformation With Quadrilaterals for Pipeline Risk Management

2004 ◽  
Author(s):  
Jeffrey R. Keaton ◽  
Richard W. Gailing
Keyword(s):  
Risk Management ◽  
Surface Deformation ◽  
Ground Deformation ◽  
Ground Surface ◽  
Repeated Measurements ◽  
Slope Deformation ◽  
Strain Gauges ◽  
Foundation Engineering ◽  
Prone Area ◽  
Soil Measurements

Ground displacements, strains, and tilts can be calculated by repeated measurements of the lengths of six chords and relative elevations of an array of four points, known as a quadrilateral. Quadrilateral measurements allow ground-surface deformation and strain to be calculated. Typically, soil-pipeline interaction results in pipeline strain being less than ground strain. Strain gauges traditionally have been used on pipelines in landslide areas to aid in managing pipeline risk. Quadrilaterals may be economical alternatives to placing strain gauges on existing pipelines in areas of active or potential slope movements. A threshold ground deformation or strain is used to trigger more expensive means of evaluating pipeline integrity. Quadrilaterals are relatively inexpensive to install, but must be carefully located and founded deep enough to avoid seasonal shrink-swell effects of the soil. Measurements must be taken with precise instruments (tape extensometer) so that small changes can be detected with acceptable errors. Three contiguous quadrilaterals were installed in Spring 2003 in a landslide-prone area of southern California to aid in monitoring a slope between the main scarp of a recently active landslide and a pipeline bridge foundation. Engineering geologic evaluation supported a conclusion that the rate of headward crest advancement would be slow, but a method of detecting and quantifying slope deformation was needed for operational risk management.

scholarly journals Multi-Sensor InSAR Assessment of Ground Deformations around Lake Mead and Its Relation to Water Level Changes

2021 ◽  
Vol 13 (3) ◽  
pp. 406
Author(s):  
Mehdi Darvishi ◽  
Georgia Destouni ◽  
Saeid Aminjafari ◽  
Fernando Jaramillo
Keyword(s):  
Water Level ◽  
Surface Deformation ◽  
Ground Deformation ◽  
Water Storage ◽  
Negative Relationship ◽  
Ground Surface ◽  
Subsurface Water ◽  
Lake Mead ◽  
Ground Deformations ◽  
Water Level Changes

Changes in subsurface water resources might alter the surrounding ground by generating subsidence or uplift, depending on geological and hydrogeological site characteristics. Improved understanding of the relationships between surface water storage and ground deformation is important for design and maintenance of hydraulic facilities and ground stability. Here, we construct one of the longest series of Interferometric Synthetic Aperture Radar (InSAR) to date, over twenty-five years, to study the relationships between water level changes and ground surface deformation in the surroundings of Lake Mead, United States, and at the site of the Hoover Dam. We use the Small Baseline Subset (SBAS) and Permanent scatterer interferometry (PSI) techniques over 177 SAR data, encompassing different SAR sensors including ERS1/2, Envisat, ALOS (PALSAR), and Sentinel-1(S1). We perform a cross-sensor examination of the relationship between water level changes and ground displacement. We found a negative relationship between water level change and ground deformation around the reservoir that was consistent across all sensors. The negative relationship was evident from the long-term changes in water level and deformation occurring from 1995 to 2014, and also from the intra-annual oscillations of the later period, 2014 to 2019, both around the reservoir and at the dam. These results suggest an elastic response of the ground surface to changes in water storage in the reservoir, both at the dam site and around the reservoir. Our study illustrates how InSAR-derived ground deformations can be consistent in time across sensors, showing the potential of detecting longer time-series of ground deformation.

scholarly journals Investigating Ground Subsidence and the Causes over the Whole Jiangsu Province, China Using Sentinel-1 SAR Data

2021 ◽  
Vol 13 (2) ◽  
pp. 179
Author(s):  
Yonghong Zhang ◽  
Hongan Wu ◽  
Mingju Li ◽  
Yonghui Kang ◽  
Zhong Lu
Keyword(s):  
Time Series ◽  
Land Surface ◽  
Surface Deformation ◽  
Underground Mining ◽  
Ground Deformation ◽  
Ground Surface ◽  
Data Retrieval ◽  
Field Work ◽  
Jiangsu Province ◽  
Ground Subsidence

Interferometric synthetic aperture radar (InSAR) mapping of localized ground surface deformation has become an important tool to manage subsidence-related geohazards. However, monitoring land surface deformation using InSAR at high spatial resolution over a large region is still a formidable task. In this paper, we report a research on investigating ground subsidence and the causes over the entire 107, 200 km2 province of Jiangsu, China, using time-series InSAR. The Sentinel-1 Interferometric Wide-swath (IW) images of 6 frames are used to map ground subsidence over the whole province for the period 2016–2018. We present processing methodology in detail, with emphasis on the three-level co-registration scheme of S-1 data, retrieval of mean subsidence velocity (MSV) and subsidence time series, and mosaicking of multiple frames of results. The MSV and subsidence time series are generated for 9,276,214 selected coherent pixels (CPs) over the Jiangsu territory. Using 688 leveling measurements in evaluation, the derived MSV map of Jiangsu province shows an accuracy of 3.9 mm/year. Moreover, subsidence causes of the province are analyzed based on InSAR-derived subsidence characteristics, historical optical images, and field-work findings. Main factors accounting for the observed subsidence include: underground mining, groundwater withdrawal, soil consolidations of marine reclamation, and land-use transition from agricultural (paddy) to industrial land. This research demonstrates not only the capability of S-1 data in mapping ground deformation over wide areas in coastal and heavily vegetated region of China, but also the potential of inferring valuable knowledge from InSAR-derived results.

scholarly journals Coseismic Ground Deformation Reproduced through Numerical Modeling: A Parameter Sensitivity Analysis

Geosciences ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 370 ◽  
Author(s):  
Panara ◽  
Toscani ◽  
Cooke ◽  
Seno ◽  
Perotti
Keyword(s):  
Stress Drop ◽  
Surface Deformation ◽  
Slip Surface ◽  
Ground Deformation ◽  
Numerical Models ◽  
Three Dimensional ◽  
Ground Surface ◽  
Line Of Sight ◽  
Coseismic Slip ◽  
2009 L’Aquila Earthquake

Coseismic ground displacements detected through remote sensing surveys are often used to invert the coseismic slip distribution on geologically reliable fault planes. We analyze a well-known case study (2009 L’Aquila earthquake) to investigate how three-dimensional (3D) slip configuration affects coseismic ground surface deformation. Different coseismic slip surface configurations reconstructed using aftershocks distribution and coseismic cracks, were tested using 3D boundary element method numerical models. The models include two with slip patches that reach the surface and three models of blind normal-slip surfaces with different configurations of slip along shallowly-dipping secondary faults. We test the sensitivity of surface deformation to variations in stress drop and rock stiffness. We compare numerical models’ results with line of sight (LOS) surface deformation detected from differential SAR (Synthetic Aperture Radar) interferometry (DInSAR). The variations in fault configuration, rock stiffness and stress drop associated with the earthquake considerably impact the pattern of surface subsidence. In particular, the models with a coseismic slip patch that does not reach the surface have a better match to the line of sight coseismic surface deformation, as well as better match to the aftershock pattern, than models with rupture that reaches the surface. The coseismic slip along shallowly dipping secondary faults seems to provide a minor contribution toward surface deformation.

Surface Deformation in Northeast Italy by using time series InSAR techniques with Sentinel-1 data

2020 ◽  
Author(s):  
Giulia Areggi ◽  
Cristiano Tolomei ◽  
Lorenzo Bonini ◽  
Giuseppe Pezzo
Keyword(s):  
Time Series ◽  
Surface Deformation ◽  
Ground Deformation ◽  
Geodetic Data ◽  
Plate Motion ◽  
Tectonic Structures ◽  
Synthetic Aperture Radar Data ◽  
Area Of Interest ◽  
Spatial Coverage ◽  
Active Tectonic

&lt;p&gt;Geodetic data provide useful information on surface deformation over long period of time. Applying time series methods to geodetic data, several phenomena were studied. In particular, the potentials of geodetic data were exploited to detect and measure slow tectonic signals such as interseismic strain accumulation. During the interseismic period, when the faults are locked, an accumulation of deformation can occur in response to active tectonic stresses. Considering that such energy can be released through earthquakes, the estimation of surface deformation and the long-term strain rate reveals itself a useful approach for seismic hazard investigations. In this study, we used remote sensing Synthetic Aperture Radar data to evaluate the ground deformation in the Southeastern Alps (Northeastern Italy), an area characterized by an active convergent regime (Adria plate motion is ~ 2mm/yr) as well as several active tectonic structures. We used SAR images provided by Sentinel-1A/B satellites spanning the 2015-2019 temporal interval by applying the multi temporal Small Baseline Subset Interferometry (SBAS) technique. The method is based on a combination of a large number of interferograms characterized by small temporal and geometric baseline in order to reduce decorrelation effects and increase the spatial coverage over the area of interest. The outcomes consist of displacement time series and a mean ground velocity map for each coherent pixels with respect to the satellite Line-of-Sight (LoS). Some detected patterns can be attributed to subsidence phenomena, affecting the plain in the area under analysis, and due to the compaction of the sediments.&lt;/p&gt;

Ground Surface Deformation Caused by the Mw 5.8 Early Strong Aftershock following the 13 November 2016 Mw 7.8 Kaikōura Mainshock

2018 ◽  
Vol 89 (6) ◽  
pp. 2214-2226
Author(s):  
Qingjun Meng ◽  
Sidao Ni ◽  
Aizhi Guo ◽  
Yong Zhou
Keyword(s):  
Surface Deformation ◽  
Ground Deformation ◽  
Ground Surface ◽  
Surface Displacement ◽  
High Rate ◽  
Observation Data ◽  
Seismic Waveforms ◽  
Finite Fault ◽  
Event Based ◽  
Fault Mechanism

ABSTRACT The Mw 7.8 Kaikōura earthquake on 13 November 2016 is one of the most complex events ever recorded, with surface rupture found on more than a dozen faults. Within about 10 minutes after the mainshock, an Mw 5.8 event occurred and caused an 8 cm static displacement at high‐rate Global Positioning System (GPS) station KAIK, which was not accounted for in previous mainshock studies. In this article, we focus on the Mw 5.8 aftershock including (1) relocating the hypocenter using the hypo2000 method, (2) conducting a grid search for its point‐source mechanism and centroid location using seismic waveforms at four nearby stations, (3) inverting finite‐fault models of this event based on grid‐searched fault mechanism, and (4) calculating the surface ground deformation and estimating the deformation in the line of sight (LoS) directions of the ascending and descending Advanced Land Observation Satellite‐2 (ALOS‐2). Although we are not able to resolve the ruptured fault of the Mw 5.8 aftershock because of limited observation data, we estimate that this event can generate 10–20 cm ground surface displacement and affect the ground displacement observed on the Interferometric Synthetic Aperture Radar (InSAR) data near the Kaikōura Peninsular.

Sign in / Sign up

Export Citation Format

Share Document