scholarly journals Seismic characterization of a clay-block rupture in Harmalière landslide, French Western Alps

2020 ◽  
Vol 221 (3) ◽  
pp. 1777-1788 ◽  
Author(s):  
S Fiolleau ◽  
D Jongmans ◽  
G Bièvre ◽  
G Chambon ◽  
L Baillet ◽  
...  
Keyword(s):  
Seismic Energy ◽  
Western Alps ◽  
Clay Material ◽  
Cumulative Number ◽  
Seismic Parameters ◽  
Seismic Characterization ◽  
Cross Correlations ◽  
The City ◽  
Rupture Mechanism

SUMMARY In late June 2016, the Harmalière clayey landslide (located 30 km south of the city of Grenoble, French Alps) was dramatically reactivated at the headscarp after a 35-yr-long period of continuous but limited activity. The total involved volume, which moved as sliding blocks of various sizes, was estimated to be about 2 × 10 6 m3. Two seismometers were installed at the rear of the main headscarp in August 2016, on both sides of a developing fracture delineating a block with a volume of a few hundred cubic metres. For 4 months, they continuously recorded seismic ambient vibrations and microearthquakes until the block broke. Five seismic parameters were derived from the monitoring: the cumulative number of microearthquakes (CNe), the seismic energy (SE), the block resonance frequency (fB), the relative variation in Rayleigh wave velocity (dV/V) deduced from noise cross-correlations between the two sensors and the associated correlation coefficient (CC). All parameters showed a significant precursory signal before the rupture, but at very different times, which indicates the complexity of the rupture mechanism in this clay material.

Seismic characterization of clays blocks ruptures in a clayey landslide, the Harmaliere landslide.

2020 ◽  
Author(s):  
Sylvain Fiolleau ◽  
Denis Jongmans ◽  
Gregory Bièvre ◽  
Guillaume Chambon ◽  
Laurent Baillet
Keyword(s):  
Resonance Frequency ◽  
Environmental Parameters ◽  
Heavy Rain ◽  
Clay Material ◽  
Rain Event ◽  
Cumulative Number ◽  
Low Frequencies ◽  
Seismic Parameters ◽  
Seismic Characterization ◽  
Over Time

<p>Many regions of the world are exposed to landslides in clayey deposits, which pose major problems for land management and human safety. Clayey landslide activity is complex, showing a succession of periods of inactivity and reactivation phases that can evolve into sudden acceleration and catastrophic landslides and/or flows. Understanding the processes that control this activity therefore requires the continuous monitoring of specific parameters. At the end of June 2016, the Harmalière clayey landslide (located 30 km south of the city of Grenoble in the French Alps) was dramatically reactivated at the headscarp after 35 years of continuous but limited activity. The total volume involved, which moved in the form of tilted blocks of different sizes, was estimated at about 3,106 m3. Several sensors, including seismometers and GNSS stations, were installed immediately behind the main escarpment in early August 2016. They recorded a rupture involving a block of a few hundred cubic meters in November 2016. Additional data (seismology, meteorology, piezometer, etc.) were provided by a permanent observatory located a few hundred meters away in the nearby Avignonet landslide (RESIF2006). Two three-component seismic sensors were placed on the collapsed block and 10 meters aft on the stable part respectively.</p><p>Thus, four seismic parameters were monitored for 4 months until the clay block rupture: the cumulative number of microseisms, the resonance frequency of the block, the relative variation in Rayleigh wave velocity (dV/V) and the correlation coefficient (CC) in the range 1-12 Hz. All these parameters showed a significant precursor signal before the rupture, but at very different times. During the monitoring period, they also showed different responses to environmental parameters and in particular to precipitation. The resonance frequency increased slightly but steadily from 8 to 9 Hz (+12%) during the pre-break period, then decreased from 9 Hz to 7 Hz (-22%) just one hour before the break. However, the other three parameters showed significant variations a few weeks before failure. The dV/V and CC parameters reacted 1.5 month before the failure, during a very heavy rain event. The CC showed a general decrease over time, first affecting the high frequencies, then gradually spreading to the low frequencies. Finally, seismic activity is almost constant during the first three months, with only slight temporary increases during precipitation. One month before the rupture, a significant increase in the number of events is observed.</p><p>This study shows the potential of monitoring different seismic parameters over time in order to predict the slip of blocks in a clay material.</p>

scholarly journals Statistics of seismicity to investigate the Campi Flegrei caldera unrest

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Tramelli ◽  
C. Godano ◽  
P. Ricciolino ◽  
F. Giudicepietro ◽  
S. Caliro ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Central Area ◽  
Seismic Energy ◽  
Progressive Increase ◽  
Campi Flegrei ◽  
Cumulative Number ◽  
Seismic Parameters ◽  
Seismicity Rate ◽  
Seismic Catalogue ◽  
Vertical Ground

AbstractThe knowledge of the dynamic of the Campi Flegrei calderic system is a primary goal to mitigate the volcanic risk in one of the most densely populated volcanic areas in the world. From 1950 to 1990 Campi Flegrei suffered three bradyseismic crises with a total uplift of 4.3 m. After 20 years of subsidence, the uplift started again in 2005 accompained by a low increment of the seismicity rate. In 2012 an increment in the seismic energy release and a variation in the gas composition of the fumaroles of Solfatara (in the central area of the caldera) were recorded. Since then, a slow and progressive increase in phenomena continued until today. We analyze the INGV - Osservatorio Vesuviano seismic catalogue of Campi Flegrei from 2000 to 2020 in order to look for any variation in the seismic parameters and compare them with geochemical monitored ones. A remarkable correlation between independent variables of earthquake cumulative number, CO/CO2 values and vertical ground deformation reveals a likely common origin. Moreover the correlation between all the variables here analysed enlightens that the same origin can cause the temporal behavior of all these variables. We interpret the seismological, geochemical and geodetic observable in terms of the injection of magmatic fluids into the hydrothermal system or its pressurization.

scholarly journals Statistics of Seismicity to Investigate the Campi Flegrei Caldera Unrest

2021 ◽  
Author(s):  
Anna Tramelli ◽  
Cataldo Godano ◽  
Patrizia Ricciolino ◽  
Flora Giudicepietro ◽  
Stefano Caliro ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Central Area ◽  
Seismic Energy ◽  
Progressive Increase ◽  
Campi Flegrei ◽  
Cumulative Number ◽  
Seismic Parameters ◽  
Seismicity Rate ◽  
Seismic Catalogue ◽  
Vertical Ground

Abstract The knowledge of the dynamic of the Campi Flegrei calderic system is a primary goal to mitigate the volcanic risk in one of the most densely populated volcanic areas in the world. From 50s to 80s Campi Flegrei suffered three bradyseismic crises with a total uplift of almost 4.3 m. After a period of subsidence of 20 years, the uplift started again in 2005 accompanied by a low increment in the seismicity rate. In 2012 an increment in the seismic energy release and a variation in the gas composition of the fumaroles of Solfatara (in the central area of the 1 caldera) were recorded. Since then, a slow and progressive increase in phenomena continued until today. We analyze the seismic catalogue of Campi Flegrei from 2000 to 2020 collected by INGV-Osservato-rio Vesuviano to look for any variation in the seismic parameters and compare them with geochemical monitored ones. A remarkable correlation between independent variables as earthquake cumulative number, CO/CO 2 values and vertical ground deformation reveals a likely common origin. The interpretation of the seismological, geochemical and geodetical observable brings back to the injection of magmatic fluids into the hydrothermal system or its pressurization.

scholarly journals On the characterization of seismic signals generated by snow avalanches for monitoring purposes

2001 ◽  
Vol 32 ◽  
pp. 268-274 ◽  
Author(s):  
E. Suriñach ◽  
G. Furdada ◽  
F. Sabot ◽  
B. Biesca ◽  
J. M. Vilaplana
Keyword(s):  
Seismic Waves ◽  
Seismic Energy ◽  
Time Lapse ◽  
Seismic Signals ◽  
Avalanche Size ◽  
Local Site ◽  
Video Images ◽  
Time Domains ◽  
Seismic Characterization

AbstractSeismic signals from artificially released avalanches were studied in an attempt to characterize them for avalanche-monitoring purposes. The seismic signals generated by different sizes and types of avalanches were recorded and analyzed in the time and frequency domains. Synchronized recordings of the corresponding seismic signals and the video images of the evolution of the avalanches were obtained together with a detailed cartography. Characteristic signatures in the frequency and time domains were found to depend on the characteristics of the avalanche path and measuring location, but to be mostly independent of avalanche size. The source of the different parts of the recorded seismic signals was determined. A relationship was observed between the avalanche size and the amplitude of the signals. Given the presence of local site effects, a prior seismic characterization of the avalanche path in relation to the recording sites is necessary for monitoring purposes. Moreover” it was found that sliding slabs in the early phase of acceleration produce little seismic energy, resulting in a time lapse between the observable start of the avalanche and the arrival of the detectable seismic waves at the receiving station.

scholarly journals Genomic investigation of a dengue virus outbreak in Thiès, Senegal, in 2018

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amy Gaye ◽  
Tolla Ndiaye ◽  
Mouhamad Sy ◽  
Awa B. Deme ◽  
Alphonse B. Thiaw ◽  
...  
Keyword(s):  
West Africa ◽  
Dengue Virus ◽  
Clinical Signs ◽  
Health Concern ◽  
Public Health Concern ◽  
Local Circulation ◽  
Viral Genomes ◽  
Genomic Characterization ◽  
The City

AbstractDengue virus is a major and rapidly growing public health concern in tropic and subtropic regions across the globe. In late 2018, Senegal experienced its largest dengue virus outbreak to date, covering several regions. However, little is known about the genetic diversity of dengue virus (DENV) in Senegal. Here we report complete viral genomes from 17 previously undetected DENV cases from the city of Thiès. In total we identified 19 cases of DENV in a cohort of 198 individuals with fever collected in October and November 2018. We detected 3 co-circulating serotypes; DENV 3 was the most frequent accounting for 11/17 sequences (65%), 4 (23%) were DENV2 and 2 (12%) were DENV1. Sequences were most similar to recent sequences from West Africa, suggesting ongoing local circulation of viral populations; however, detailed inference is limited by the scarcity of available genomic data. We did not find clear associations with reported clinical signs or symptoms, highlighting the importance of testing for diagnosing febrile diseases. Overall, these findings expand the known range of DENV in Senegal, and underscore the need for better genomic characterization of DENV in West Africa.

scholarly journals Characterization of Spatial Planning in Brazil: The Right to the City in Theory and Practice

2019 ◽  
Vol 34 (4) ◽  
pp. 419-437 ◽  
Author(s):  
Roberto Rocco ◽  
Luciana Royer ◽  
Fábio Mariz Gonçalves
Keyword(s):  
Spatial Planning ◽  
Theory And Practice ◽  
Right To The City ◽  
The Right ◽  
The City

Seismic Characterization of the Shuaiba Formation in the Western Region of UAE, a Predictive Tool to unravel Shuaiba Facies Mosaic?

2017 ◽  
Author(s):  
Valentina Zampetti ◽  
Sonia Perrotta ◽  
Ghassen Chaari ◽  
Thomas Krayenbuehl ◽  
Matthias Braun ◽  
...  
Keyword(s):  
Western Region ◽  
Predictive Tool ◽  
Seismic Characterization ◽  
The Western Region

Study of Painting Materials and Techniques in the 18th Century St.Athanasius Church in Moschopolis, Albania

2007 ◽  
Vol 1047 ◽  
Author(s):  
Eleni Pavlidou ◽  
N. Civici ◽  
E. Caushi ◽  
L. Anastasiou ◽  
T. Zorba ◽  
...  
Keyword(s):  
18Th Century ◽  
Orthodox Church ◽  
Wall Paintings ◽  
Cultural Center ◽  
Green Earth ◽  
Almost All ◽  
The City ◽  
The Church ◽  
Compositional Characterization

AbstractIn this paper are presented the studies of the paint materials and the technique used in 18th century wall paintings, originated from the orthodox church of St Athanasius, in the city of Maschopolis, a flourishing economical and cultural center, in Albania. The church was painted in 1745 by Konstantinos and Athanasios Zografi, and during the last years, restoration activities are being performed at the church. Samples that included plasters and pigments of different colors were collected from important points of the wall paintings. Additionally, as some parts of the wall-paintings were over-painted, the analysis was extended to the compositional characterization of these areas. The identification of the used materials was done by using complementary analytical methods such as Optical Microscopy, Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM-EDS) and X-ray fluorescence (TXRF).The presence of calcite in almost all the pigments is indicative for the use of the fresco technique at the studied areas, while the detection of gypsum and calcium oxalate, indicates an environmental degradation along with a biodegradation. Common pigments used in this area at 15-16th centuries, such as cinnabar, green earth, manganese oxide, carbon black and calcite were identified.

scholarly journals Surface and Underground Geomechanical Characterization of an Area Affected by Instability Phenomena in Zaruma Mining Zone (Ecuador)

2021 ◽  
Vol 13 (6) ◽  
pp. 3272
Author(s):  
Paúl Carrión-Mero ◽  
Maribel Aguilar-Aguilar ◽  
Fernando Morante-Carballo ◽  
María José Domínguez-Cuesta ◽  
Cristhian Sánchez-Padilla ◽  
...  
Keyword(s):  
Mass Movement ◽  
Mining Activity ◽  
Mining District ◽  
Mean Values ◽  
Surface Areas ◽  
Definition Of ◽  
Action Measures ◽  
Geomechanical Characterization ◽  
The City

In the last decade, in the mining district of Zaruma-Portovelo, there has been significant land subsidence related to uncontrolled mining activity. The purpose of this work was to carry out a surface and underground geomechanical characterization of a mining sector north of the city of Zaruma that allows the definition of potentially unstable areas susceptible to the mass movement. The methodology used consists of the following stages: (i) compilation of previous studies; (ii) surface and underground characterization of rocky material to establish its susceptibility to mass movement; (iii) interpretation of results; and (iv) proposal of action measures. Among the most relevant results, it stands out that 26.1% of the 23 stations characterized on the surface present conditions that vary from potentially unstable to unstable. In underground galleries, the studied mean values of the 17 stations indicate that the rock has a medium to good quality, representing a medium susceptibility to gallery destabilization. The results obtained for the surface areas (depths up to 50 m, where altered materials predominate) and the underground areas (depths > 50 m, where the alterations are specific) can be used to identify the areas with a more significant potential for instability. For both cases, it has been possible to define specific monitoring, control, and planning actions for sensitive areas.

Possibility of using compensatory urban drainage techniques as leisure units to expand public areas into subdivisions

2021 ◽  
Vol 13 ◽  
Author(s):  
Geovana Geloni Parra ◽  
Bernardo Arantes do Nascimento Teixeira ◽  
Érico Masiero ◽  
Thais Borges Martins Rodrigues
Keyword(s):  
Social Interest ◽  
Urban Drainage ◽  
Rain Gardens ◽  
Public Areas ◽  
Retention Basin ◽  
Housing Complex ◽  
The City ◽  
Housing Estates ◽  
Drainage Technique

Abstract Many housing estates of social interest have not contributed to implementing leisure areas and reducing their environmental and urban quality. This paper aims to propose a leisure unit using a compensatory urban drainage technique in a housing complex of social interest in the city of São José do Rio Preto, São Paulo, Brazil. The characterization of the area, land use and occupation surveys, area sectorization, and catchment division were carried out. Afterwards, proposals for interventions based on surface runoff were presented using calculations of existing runoff and future scenarios. Results related to environmental and social gains for the area are discussed, as well as the possibility of implementing decentralized compensatory techniques. Moreover, 156 rain gardens and 3 ditches were proposed throughout the subdivisions, which enabled a gain of 989m² of contribution area to infiltrate the whole area, and the use of the retention basin as a leisure area. The total storage volume achieved with the sum of all the techniques implemented was approximately 3,000 cubic meters more than that projected for the existing retention basin.

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