First results after the deployment of a subsea geodetic monitoring system

2021 ◽  
Author(s):  
Pierre-François Adam ◽  
Nathalie Olivier ◽  
David Jaouen
Keyword(s):  
Velocity Profile ◽  
Monitoring System ◽  
Active Faults ◽  
Monitoring Program ◽  
Line Of Sight ◽  
Tectonic Plates ◽  
Sound Velocity Profile ◽  
The North ◽  
First Results

<p>Geodetic networks at sea are necessary to monitor active faults and the long term displacement of tectonic plates. iXblue has developed a new integrated subsea monitoring system: Canopus</p><p>The Canopus transponders are enable to regularly measure precisely the distance between the transponders that are in acoustic line of sight. The measurement are stored in a memory inside each beacon and can be collected from surface using acoustic modem. In collaboration with the IUEM, and in the framework of ERC Focus project, 8 Canopus beacons were deployed at each side of the North Alfeo Fault in Sicilia for a  4 years monitoring program. To prepare the deployment, a first experiment took place in Brest Bay in July 2019, and a second one in La Ciotat Bay in September 2020. Thanks to Delph subsea positioning software, simulations enable to confirm acoustic line of sight between beacons considering the local bathymetry, the sound velocity profile and the height of the transponders above the seabed. The final deployment took place in October 2020.  We present here the series of test and  simulations conducted before the final deployment and the first results after deployment.</p>

scholarly journals Observation of the rock slope thermal regime, coupled with crack meter stability monitoring

2021 ◽  
Author(s):  
Ondřej Racek ◽  
Jan Blahůt ◽  
Filip Hartvich
Keyword(s):  
Rock Mass ◽  
Monitoring System ◽  
Rock Slope ◽  
Global Radiation ◽  
Environmental Parameters ◽  
Radiation Balance ◽  
Rock Types ◽  
Novel Approach ◽  
First Results

Abstract. This article describes an innovative, complex and affordable monitoring system designed for joint observation of environmental parameters, rock block dilatations and temperature distribution inside the rock mass with a newly designed 3-meter borehole temperature sensor. Global radiation balance data are provided by pyranometers. The system introduces a novel approach for internal rock mass temperature measurement, which is crucial for the assessment of the changes in the stress field inside the rock slope influencing its stability. The innovative approach uses an almost identical monitoring system at different sites allowing easy setup, modularity and comparison of results. The components of the monitoring system are cheap, off-the-shelf and easy to replace. Using this newly designed system, we are currently monitoring three different sites, where the potential rock fall may endanger society assets below. The first results show differences between instrumented sites, although data time-series are relatively short. Temperature run inside the rock mass differs for each site significantly. This is very likely caused by different aspects of the rock slopes and different rock types. By further monitoring and data processing, using advanced modelling approaches, we expect to explain the differences among the sites, the influence of rock type, aspect and environmental variables on the long-term slope stability.

scholarly journals The Louisiana Amphibian Monitoring Program from 1997 to 2017: Results, analyses, and lessons learned

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257869
Author(s):  
Jacoby Carter ◽  
Darren Johnson ◽  
Jeff Boundy ◽  
William Vermillion
Keyword(s):  
Urban Areas ◽  
Monitoring Program ◽  
Lessons Learned ◽  
The North ◽  
Osteopilus Septentrionalis ◽  
Species Lists ◽  
Demographic Patterns ◽  
North And South ◽  
Term Monitoring

To determine trends in either frog distribution or abundance in the State of Louisiana, we reviewed and analyzed frog call data from the Louisiana Amphibian Monitoring Program (LAMP). The data were collected between 1997 and 2017 using North American Amphibian Monitoring Program protocols. Louisiana was divided into three survey regions for administration and analysis: the Florida Parishes, and 2 areas west of the Florida parishes called North and South. Fifty-four routes were surveyed with over 12,792 stops and 1,066 hours of observation. Observers heard 26 species of the 31 species reported to be in Louisiana. Three of the species not heard were natives with ranges that did not overlap with survey routes. The other two species were introduced species, the Rio Grande Chirping Frog (Eleutherodactylus cystignathoides) and the Cuban Treefrog (Osteopilus septentrionalis). Both seem to be limited to urban areas with little to no route coverage. The 15 most commonly occurring species were examined in detail using the percentage of stops at which they observed along a given survey and their call indices. Most species exhibited a multimodal, concave, or convex pattern of abundance over a 15-year period. Among LAMP survey regions, none of the species had synchronous population trends. Only one group of species, winter callers, regularly co-occur. Based on the species lists, the North region could be seen as a subset of the South. However, based on relative abundance, the North was more similar to Florida parishes for both the winter and summer survey runs. Our analyses demonstrate that long-term monitoring (10 years or more) may be necessary to determine population and occupancy trends, and that frog species may have different local demographic patterns across large geographic areas.

Long-term monitoring of coastal saltwater intrusion using the geoelectrical monitoring system SAMOS

2021 ◽  
Author(s):  
Michael Grinat ◽  
Mathias Ronczka ◽  
Thomas Günther ◽  
Dieter Epping ◽  
Vitali Kipke ◽  
...  
Keyword(s):  
Groundwater Recharge ◽  
Monitoring System ◽  
North Sea ◽  
Early Warning ◽  
Groundwater System ◽  
Transition Zones ◽  
The North ◽  
The North Sea ◽  
Local Water

<p>Efficient groundwater management is the key to a sustainable use of freshwater aquifers. In the coastal areas worldwide, saltwater intrusions caused by sea-level rise, overuse of freshwater resources and changing groundwater recharge is a major threat to the availability of freshwater. A reduced groundwater recharge combined with an increased extraction can lead to vertical upconing or lateral movement of the freshwater-saltwater transition zones, therefore reducing the local freshwater resources. Long-term and continuous observation of the freshwater-saltwater transition zones is crucial to implement early warning procedures, yields more detailed insight into the groundwater system and therefore enables early adjustment and adaptation of extraction rates if needed.</p><p>The SAltwater MOnitoring System (SAMOS) consists of two main parts: a vertical electrode chain of steel ring electrodes permanently installed in a backfilled borehole and a measuring system at the surface. The number of electrodes (commonly about 80) and distance between adjacent electrodes (commonly about 25 cm) is generally flexible. The chain of electrodes is connected to a lightweight and small resistivity meter (LGM, 4-Point light 10W). Thanks to the maximum output current of 100 mA and a voltage of 380 V a low power consumption is achieved and long-term and autonomous monitoring is enabled by solar panel based power supply. Furthermore, the system is designed to run predefined measurement protocols and transfers the data to a remote server immediately after a measurement is performed. SAMOS is commonly installed in the transition zone between fresh- and saltwater allowing the detection of very slight resistivity changes (less than 1 Ohmmeter). While first systems were completely manufactured by LIAG, the latest subsurface systems were built by Solexperts which allowed us to include temperature sensors.</p><p>We present data from four SAMOS systems currently running at different locations. Two of them are installed in the central part of the freshwater lense of the North Sea island Borkum (in cooperation with Stadtwerke Borkum) in depths between 44 m and 65 m below the surface, close to freshwater wells of the local water supplier, thus monitoring the overall groundwater system and delivering data since 2009. Even though measurements immediately after the installation are disturbed by the drilling process and an adjustment to undisturbed natural conditions is observed, adapted inversion schemes allow to use all data. While in most cases only slight resistivity changes are observed up to now, at some depths larger seasonal resistivity changes occur at one Borkum site that can mostly be explained by changes of the groundwater recharge rate and changing pumping activities in a water catchment area. Two further systems have been installed in 2018 and 2020. One is located behind the dune line at the edge of the freshwater lense on the North Sea island Spiekeroog. In cooperation with the local water supply company OOWV (Oldenburg-Ostfriesischer Wasserverband) another system for their groundwater extraction fields is installed near Jever several kilometers from the coast-line used for early warning.</p>

scholarly journals The TAPS Project. 2: Challenges and pitfalls of community interviewing

1990 ◽  
Vol 14 (11) ◽  
pp. 651-653 ◽  
Author(s):  
David Dayson
Keyword(s):  
Mentally Ill ◽  
Psychiatric Services ◽  
Hospital Services ◽  
Scientific Presentation ◽  
North East ◽  
The North ◽  
First Results ◽  
Subjective View

From November 1987 until March 1990 I worked as a researcher with the TAPS project. So far this project's task has been to evaluate the reprovision of hospital services for the long-term mentally ill from two hospitals in the North East Thames Region (Team for the Assessment of Psychiatric Services, 1988). My work involved gathering clinical and social data from over 250 patients and their carers after they had spent a year out of hospital. Most of these patients were suffering from schizophrenia. The design and first results (Team for the Assessment of Psychiatric Services, 1990) provide an objective account of this research. In contrast, this paper intends to put forth a subjective view of some of the problems encountered while obtaining these data in the community. This situation faced the researcher with unique and challenging circumstances that are not normally discussed in the scientific presentation of follow-up data. Its aim is to pre-empt similar difficulties for other community reserarch by providing guidelines. I am going to cover three areas: arranging interviews, conducting them safely, and handling situations that necessitate stepping out of the interviewer role.

scholarly journals First Results of a Near IR Monitoring Program of OH/IR Stars

1993 ◽  
Vol 155 ◽  
pp. 330-330
Author(s):  
P. García-Lario ◽  
D. Engels ◽  
A. Manchado
Keyword(s):  
Point Source ◽  
Near Infrared ◽  
Monitoring Program ◽  
Near Ir ◽  
Ir Stars ◽  
First Results ◽  
Long Term Monitoring ◽  
Term Monitoring

We present the first results of a long-term monitoring program of observations in the near infrared of a selected sample of OH/IR stars included in the IRAS Point Source Catalogue. The observations have been made using the 1.5m Sanchez Magro Telescope (SMT) at Izaña (Tenerife, Spain) since the beginning of 1991 and are still in progress. They are being complemented with observations made using the 1m ESO photometric telescope (La Silla, Chile). The sample includes 30 OH/IR stars with a variety of infrared and OH maser luminosities, expansion velocities, LRS classes and position in the IRAS two-colour diagram.

scholarly journals Stochastic relation between anomalous propagation in the line-of-sight VHF radio band and occurrences of earthquakes

2013 ◽  
Vol 1 (6) ◽  
pp. 6829-6848
Author(s):  
K. Motojima ◽  
N. Haga
Keyword(s):  
Statistical Analysis ◽  
Monitoring System ◽  
Line Of Sight ◽  
Radio Broadcasting ◽  
Fm Radio ◽  
Line Of Sight Propagation ◽  
Propagation Paths ◽  
Anomalous Propagation ◽  
Radio Band

Abstract. This paper was intended to find out any relation between anomalous line-of-sight propagation on the VHF band and occurrences of earthquakes near the VHF propagation paths. The television and FM radio broadcasting waves on the VHF band were monitored continuously over the long term. For that purpose, a multidirectional VHF band monitoring system was established and utilized. Anomalous line-of-sight propagation on the VHF band was distinguished from the monitored wave by using a statistical analysis. After the stochastic consideration, it was found out that earthquakes associated with anomalous propagation were characterized by magnitude of earthquakes M ≥ 4.5, and distances from epicenters L ≤ 75 km. The anomalous propagation was monitored on the VHF band a few days earlier the associated earthquakes occurred. Moreover, the anomaly appeared on multidirectional propagation paths simultaneously. The anomaly on the line-of-sight propagation indicates possibility of narrow focusing the area of epicenter of earthquake.

scholarly journals New Results from an ATCA Study of Intraday Variable Radio Sources

2002 ◽  
Vol 19 (1) ◽  
pp. 29-33 ◽  
Author(s):  
H. E. Bignall ◽  
D. L. Jauncey ◽  
L. L. Kedziora-Chudczer ◽  
J. E. J. Lovell ◽  
J.-P. Macquart ◽  
...  
Keyword(s):  
Data Analysis ◽  
Annual Cycle ◽  
Monitoring Program ◽  
Radio Sources ◽  
First Results ◽  
Observational Program ◽  
Variable Radio ◽  
Intraday Variability

AbstractWe are undertaking an observational program using the ATCA to monitor the intraday variability (IDV) of a sample of sources at 4.8 and 8.6 GHz. The sources were selected to include the known strong southern IDV sources plus a number of sources whose IDV was recently discovered. The present monitoring program will extend over a full year in order to search for any annual cycle that may be present in the long-term IDV characteristics of these sources. In this paper we discuss the observing strategy and data analysis, and present the first results from our observations.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

Stents for the Treatment of Aortic Aneurysms

1999 ◽  
Vol 82 (S 01) ◽  
pp. 171-175 ◽  
Author(s):  
D. Ebert ◽  
M. Langer ◽  
P. Uhrmeister
Keyword(s):  
Endovascular Treatment ◽  
Endovascular Repair ◽  
Abdominal Aortic Aneurysms ◽  
Aortic Aneurysms ◽  
Imaging Modalities ◽  
Exclusion Criteria ◽  
Multicenter Studies ◽  
Abdominal Aortic ◽  
First Results

SummaryThe endovascular treatment of abdominal aortic aneurysms has generated a great deal of interest since the early 1990s, and many different devices are currently available. The procedure of endovascular repair has been evaluated in many institutions and the different devices are compared. The first results were encouraging, but complications like endoleak, dislocation or thrombosis of the graft occurred. By the available devices the stent application is only promising, if the known exclusion criteria are strictly respected. Therefore a careful preinterventional assessment of the patient by different imaging modalities is necessary. As the available results up to now are preliminary and the durability of the devices has to be controlled, multicenter studies are required to improve the devices and observe their long- term success in the exclusion of abdominal aortic aneurysms.

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