scholarly journals On the Rainfall Triggering of Phlegraean Fields Volcanic Tremors

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 154
Author(s):  
Nicola Scafetta ◽  
Adriano Mazzarella
Keyword(s):  
Daily Rainfall ◽  
Water Infiltration ◽  
Campi Flegrei ◽  
Phlegraean Fields ◽  
Meteorological Observatory ◽  
Seismic Swarms ◽  
Rainfall Model ◽  
Strength And Stiffness ◽  
Water Saturated ◽  
Long Timescales

We study whether the shallow volcanic seismic tremors related to the bradyseism observed at the Phlegraean Fields (Campi Flegrei, Pozzuoli, and Naples) from 2008 to 2020 by the Osservatorio Vesuviano could be partially triggered by local rainfall events. We use the daily rainfall record measured at the nearby Meteorological Observatory of San Marcellino in Naples and develop two empirical models to simulate the local seismicity starting from the hypothesized rainfall-water effect under different scenarios. We found statistically significant correlations between the volcanic tremors at the Phlegraean Fields and our rainfall model during years of low bradyseism. More specifically, we observe that large amounts and continuous periods of rainfall could trigger, from a few days to 1 or 2 weeks, seismic swarms with magnitudes up to M = 3. The results indicate that, on long timescales, the seismicity at the Phlegraean Fields is very sensitive to the endogenous pressure from the deep magmatic system causing the bradyseism, but meteoric water infiltration could play an important triggering effect on short timescales of days or weeks. Rainfall water likely penetrates deeply into the highly fractured and hot shallow-water-saturated subsurface that characterizes the region, reduces the strength and stiffness of the soil and, finally, boils when it mixes with the hot hydrothermal magmatic fluids migrating upward. The structural collapse of the saturated fractured soil and the mixing of the meteoric fluid with the hot deep fluids triggers the local seismic activity.

Numerical Modelling of Injection-induced Seismicity at Campi Flegrei Caldera, Southern Italy

2021 ◽  
Author(s):  
Waheed Gbenga Akande ◽  
Quan Gan ◽  
David G. Cornwell ◽  
Luca De Siena
Keyword(s):  
Numerical Modelling ◽  
Induced Seismicity ◽  
Southern Italy ◽  
Rock Physics ◽  
Critical Factor ◽  
Fault Reactivation ◽  
Hot Water ◽  
Campi Flegrei ◽  
Campi Flegrei Caldera ◽  
Seismic Swarms

<p>Modelling volcanic processes at active volcanoes often requires a multidisciplinary approach, which adequately describes the complex and ever-dynamic nature of volcanic unrests. Campi Flegrei caldera (southern Italy) is an ideal laboratory where numerical modelling of injection-induced seismicity could be tested to match the observed seismicity. In the current study, thermal-hydraulic-mechanical (THM) effects of hot-water (fluid) injections were investigated to ascertain whether the observed seismicity (past and ongoing seismic swarms) could be quantitatively reproduced and modelled in isothermal or non-isothermal approximations. Fluid-flow modelling was carried out using a coupled TOUGHREACT-FLAC<sup>3D</sup> approach to simulate THM effects of fluid injections in a capped reservoir, where the sealing formation serves as a geological interface between supercritical reservoir and fractured shallow layers of the caldera. Results from previous seismic, deformation, tomographic and rock physics studies were used to constrain the model for realistic volcano modelling. The results indicated that fluid injections generated overpressure beneath the caprock and subjected it to different stress regimes at its top and bottom, and this prompted deformation. Thus, caprock deformation, triggered by injection-induced basal compressional forces and top extensional fractures, is a critical factor determining the required timing for pressure build-up and fault reactivation, and magnitudes of seismicity. Higher fluid injection rates and temperature contrasts, heterogeneity due to fault and its contrast with the host rock, and caprock hydraulic properties were among the identified secondary factors modulating fault reactivation and seismicity. Simulation results revealed that seismicity can be better modelled in isothermal (HM) approximations. A comparative study of the THM-modelled seismicity and 4-month-long (August 5<sup>th</sup> to December 5<sup>th</sup>, 2019) seismic monitoring data recorded at the Osservatorio Vesuviano showed that our model reproduced the magnitudes and depths (~2.5 Ms within 2 km) at the onset of the ongoing unrests on October 5<sup>th</sup>, 2019. However, the model could not adequately reproduce the highest magnitude (3.3 Ms at 2.57 km) seismicity on April 26<sup>th</sup>, 2020 observed since 1984 major unrests.</p><p> </p>

scholarly journals The July-August 2000 seismic swarms at Campi Flegrei Volcanic Complex, Italy

2001 ◽  
Vol 28 (13) ◽  
pp. 2525-2528 ◽  
Author(s):  
Gilberto Saccorotti ◽  
Francesca Bianco ◽  
Mario Castellano ◽  
Edoardo Del Pezzo
Keyword(s):  
Campi Flegrei ◽  
Volcanic Complex ◽  
Seismic Swarms

scholarly journals Option pricing of weather derivatives based on a stochastic daily rainfall model with Analogue Year component

Heliyon ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. e03212 ◽  
Author(s):  
Tesfahun Berhane ◽  
Nurilign Shibabaw ◽  
Gurju Awgichew ◽  
Tesfaye Kebede
Keyword(s):  
Option Pricing ◽  
Daily Rainfall ◽  
Weather Derivatives ◽  
Rainfall Model

scholarly journals Stability analysis of Baishuihe landslide under the combined effect of reservoir and rainfall

2021 ◽  
Vol 276 ◽  
pp. 01003
Author(s):  
Yi Liu ◽  
Binbin Zhao ◽  
Bin Liu ◽  
Xiaoang Kong ◽  
Zhi Yang
Keyword(s):  
Daily Rainfall ◽  
Three Gorges ◽  
Landslide Stability ◽  
The Three Gorges ◽  
Reservoir Drawdown ◽  
Two Factors ◽  
Rainfall Model ◽  
The Stability ◽  
Baishuihe Landslide ◽  
New Reservoir

Reservoir drawdown and rainfall have important influence on bank landslides, but existing research on these two factors is too idealistic. A new reservoir drawdown model was proposed for the rapid drawdown stage based on the consideration of reduction, navigation and power generation. A rainfall model was proposed considering actural rainfall and rainfall time based on fifty years of daily rainfall data. At last, taking Baishuihe landslide as an example, the landslide stability was analyzed under the combined influenced of rainfall and reservoir drawdown. Results show that the Baishuihe landslide is mainly influenced by reservoir drawdown. The terminal reservoir drawdown model can reduce the effect of continuous decline of reservoir on landslide and the stability decreases about 0.7%~1.2% compared with normal scenario. The reservoir drawdown model proposed in this paper is of significance to the reservoir operation in the Three Gorges Reservoir.

Study on water infiltration characteristics in Gotjawal (forest on lava flow) wetland area

2020 ◽  
Author(s):  
Jaehoon Kim ◽  
Hyungsoon Choi ◽  
Kukman Song ◽  
Yangji Kim ◽  
Byungki Choi ◽  
...  
Keyword(s):  
Water Level ◽  
Lava Flow ◽  
Soil Layer ◽  
Daily Rainfall ◽  
Water Infiltration ◽  
Annual Rainfall ◽  
Rainfall Events ◽  
Long Time ◽  
Conservation Plan ◽  
The Republic

<p>Gotjawal is forest that was formed by the lava flow along the slopes as a result of the volcanic activity of the parasite volcanoes which distributed over Jeju Island, the Republic of Korea. Since Gotjawal has very shallow soil layer and wetland in Gotjawal does not have water for a long time, infiltration characteristics are very important. Study wetland is 48m in diameter and 2.2m in depth and water level change with respect to time was measured in 2019. The results showed that annual rainfall in this area was measured to 2,748mm and 5 rainfall events with daily rainfall more than 100mm were recorded in 2019. When the wetland was full of water, the period of drainage was 12 days. Water level started to change when the rainfall was 43~70mm taking 10~15 hours and this seems to vary depending on the period of no rainfall. This result will be helpful for estimating groundwater sources in lava flows area and for developing conservation plan of Gotjawal.</p>

scholarly journals Development and evaluation of a stochastic daily rainfall model with long-term variability

2017 ◽  
Vol 21 (12) ◽  
pp. 6541-6558 ◽  
Author(s):  
A. F. M. Kamal Chowdhury ◽  
Natalie Lockart ◽  
Garry Willgoose ◽  
George Kuczera ◽  
Anthony S. Kiem ◽  
...  
Keyword(s):  
Gamma Distribution ◽  
Transition Probabilities ◽  
Daily Rainfall ◽  
Primary Objective ◽  
Generation Model ◽  
Gamma Model ◽  
Rainfall Occurrence ◽  
Rainfall Model ◽  
Two Parameters

Abstract. The primary objective of this study is to develop a stochastic rainfall generation model that can match not only the short resolution (daily) variability but also the longer resolution (monthly to multiyear) variability of observed rainfall. This study has developed a Markov chain (MC) model, which uses a two-state MC process with two parameters (wet-to-wet and dry-to-dry transition probabilities) to simulate rainfall occurrence and a gamma distribution with two parameters (mean and standard deviation of wet day rainfall) to simulate wet day rainfall depths. Starting with the traditional MC-gamma model with deterministic parameters, this study has developed and assessed four other variants of the MC-gamma model with different parameterisations. The key finding is that if the parameters of the gamma distribution are randomly sampled each year from fitted distributions rather than fixed parameters with time, the variability of rainfall depths at both short and longer temporal resolutions can be preserved, while the variability of wet periods (i.e. number of wet days and mean length of wet spell) can be preserved by decadally varied MC parameters. This is a straightforward enhancement to the traditional simplest MC model and is both objective and parsimonious.

Sign in / Sign up

Export Citation Format

Share Document