scholarly journals Granger Causality Analysis of Geophysical, Geodetic and Geochemical Observations during Volcanic Unrest: A Case Study in the Campi Flegrei Caldera (Italy)

Geosciences ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 185
Author(s):  
Simona Tripaldi ◽  
Sergio Scippacercola ◽  
Annarita Mangiacapra ◽  
Zaccaria Petrillo
Keyword(s):  
Granger Causality ◽  
Ground Deformation ◽  
Campi Flegrei ◽  
Test Results ◽  
Time Data ◽  
Causality Test ◽  
Campi Flegrei Caldera ◽  
System Pressure ◽  
Deformation Velocity ◽  
Granger Test

The recent signs of reawakening at Campi Flegrei caldera (Southern Italy) received a great deal of attention due to the issues related to the volcanic risk management in a densely populated area. This paper explores relations between ground deformations, seismicity and geochemical time series in the time span 2004–2016. The aim is to unravel primary processes of unrest and the related indicators which may change in time. Data structure and interactions among variables were examined applying the clustering analysis, the correlations and the Granger causality test. The hierarchical agglomerative clustering detected two sub-periods which were further investigated. In both sub-period causal links were observed between variables while correlations did not appear and vice versa. Thus, well established formal approaches are required to study causal relations. Granger test results indicate that during 2004–2011 the awakening unrest could be mainly ascribed to hydrothermal system pressure fluctuations, probably induced by deep-rooted fluids injection, and that ground deformation together with CO2/H2O appears the most suitable geo-indicators. The 2011–2016 sub-period is characterized by enhanced dynamical connectivity. Granger test results suggest that the unrest is driven by a more localized and shallower thermohydromechanical engine. CO/CO2, He/CH4 and ground deformation velocity are mutually interacting appearing the most suitable geo-indicators.

Correlation between submerged and continental infill at Campi Flegrei caldera: insights on the volcano-tectonic events of the last 15 kyr

2020 ◽  
Author(s):  
Jacopo Natale ◽  
Stefano Vitale ◽  
Roberto Isaia ◽  
Francesco D'Assisi Tramparulo ◽  
Luigi Ferranti ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Relevant Information ◽  
Seismic Facies ◽  
Campi Flegrei ◽  
Sea Level Changes ◽  
Volcanic System ◽  
Campi Flegrei Caldera ◽  
Reflection Seismic ◽  
Continental Deposits ◽  
Seismic Facies Analysis

<p>The Campi Flegrei caldera (southern Italy) is characterized by over one-third of its extension lying below the sea. In the last 15 ka the caldera floor has suffered hundreds of meters of ground deformation alternating uplift and subsidence episodes in response to the activity of the volcanic system. The evidence of significant uplifts is witnessed by the occurrence of marine sequences exposed on land, both along a 30 m high La Starza cliff and in numerous well logs. However, most of these sediments are currently hidden below the sea. This work aims to reconstruct the marine counterpart of the infill by using large multiscale reflection seismic data (>100 profiles) and an accurate seismic facies analysis. The latter consisted in the study and<br>comparison of seismic attributes, scaled to the resolution of the different datasets, to their geological analogs on land. Furthermore, by observing the changes in the pattern of on-lap terminations, thickness, amplitude, and distribution of erosive features of different horizons, we tentatively ascribed these sequences to the well-known continental deposits. The study of the whole sequence above the Neapolitan Yellow Tuff (15 ka) allowed us to gather relevant information about the relationships between stratigraphic record, ground deformation and sea-level changes. In particular, the reconstruction of buried surfaces gave us hints on the evolution of the volcanic system including the role of faults in terms of estimation of displacement and relationships with the different epoch of major eruptive activity.</p>

Offshore ground movements in the Campi Flegrei caldera during the last ~12 ka

2021 ◽  
Author(s):  
Camilla Marino ◽  
Luigi Ferranti ◽  
Jacopo Natale ◽  
Marco Sacchi ◽  
Marco Anzidei
Keyword(s):  
High Resolution ◽  
Ground Deformation ◽  
Vertical Displacement ◽  
Ground Movement ◽  
Campi Flegrei ◽  
Caldera Collapse ◽  
Deformation Pattern ◽  
Central Dome ◽  
Ground Movements ◽  
Campi Flegrei Caldera

<p>Appraisal of morphodepositional markers tied to ancient sea-levels in high-resolution seismic profiles together with geo-archaeological markers along the coast of the Pozzuoli Bay provided insights into the vertical deformation of the submerged part of the Campi Flegrei caldera (Southern Italy).</p><p>The collapse of the central part of the Campi Flegrei caldera is associated with the eruption of the Neapolitan Yellow Tuff (NYT) at ~15 ka. The NYT caldera collapse was followed by central dome resurgence associated with alternations of fast uplift and subsidence displacements that accompanied with discrete phases of intra-caldera volcanic activity. Previously, the evolution of ground movement in the Campi Flegrei caldera has been reconstructed using marine deposits uplifted onland or archaeological evidence and historical accounts and thus offers a mainly 2D appraisal of the deformation pattern. However, a complete reconstruction of post-collapse deformation suffers of the limitation that nearly two-thirds of the caldera are submerged beneath the Pozzuoli Bay.</p><p>We contribute to fill this gap by providing a reconstruction of offshore and coastal deformation through estimation of the vertical displacement of morphodepositional markers in high-resolution seismic reflection profiles and geoarchaeological markers directly surveyed at shallow depths. Our interpretation reveals the occurrence of different sediment stacking pattern whose provides evidence of rapid and oscillating ground movements. Whereas the offshore morphodepositional markers provide displacement information for the last ~12 ka, for the last ~2 ka our interpretation is supported by ancient Roman sea-level indicators. The multi-dataset analysis has allowed disentangling the signal related to the post-caldera dynamics from a broader deformation signal that affects this part of the extensional margin of the Apennines.</p><p>The integration of offshore data in the study of past episodes of ground deformation, by yielding a more complete picture of the ground motions associated to the post-collapse evolution of the Campi Flegrei caldera, bears a significant contribution for a 3D reconstruction of this high-risk resurgence caldera. Besides, the multidisciplinary approach presented here can be relevant for investigations of other calderas spanning the sea-land transition.</p>

scholarly journals A 2-D FEM thermal model to simulate water flow in a porous media: Campi Flegrei caldera case study

2012 ◽  
Vol 19 (3) ◽  
pp. 323-333 ◽  
Author(s):  
V. Romano ◽  
U. Tammaro ◽  
P. Capuano
Keyword(s):  
Porous Medium ◽  
Water Flow ◽  
Thermal Model ◽  
Ground Deformation ◽  
Campi Flegrei ◽  
Magmatic Fluid ◽  
Geothermal System ◽  
Thermal Source ◽  
Campi Flegrei Caldera ◽  
Vertical Displacements

Abstract. Volcanic and geothermal aspects both exist in many geologically young areas. In these areas the heat transfer process is of fundamental importance, so that the thermal and fluid-dynamic processes characterizing a viscous fluid in a porous medium are very important to understand the complex dynamics of the these areas. The Campi Flegrei caldera, located west of the city of Naples, within the central-southern sector of the large graben of Campanian plain, is a region where both volcanic and geothermal phenomena are present. The upper part of the geothermal system can be considered roughly as a succession of volcanic porous material (tuff) saturated by a mixture formed mainly by water and carbon dioxide. We have implemented a finite elements approach in transient conditions to simulate water flow in a 2-D porous medium to model the changes of temperature in the geothermal system due to magmatic fluid inflow, accounting for a transient phase, not considered in the analytical solutions and fluid compressibility. The thermal model is described by means of conductive/convective equations, in which we propose a thermal source represented by a parabolic shape function to better simulate an increase of temperature in the central part (magma chamber) of a box, simulating the Campi Flegrei caldera and using more recent evaluations, from literature, for the medium's parameters (specific heat capacity, density, thermal conductivity, permeability). A best-fit velocity for the permeant is evaluated by comparing the simulated temperatures with those measured in wells drilled by Agip (Italian Oil Agency) in the 1980s in the framework of geothermal exploration. A few tens of days are enough to reach the thermal steady state, showing the quick response of the system to heat injection. The increase in the pressure due to the heat transport is then used to compute ground deformation, in particular the vertical displacements characteristics of the Campi Flegrei caldera behaviour. The vertical displacements range from 1 cm to 10 cm in accordance with the mini uplift, characterizing the recent behaviour of the caldera. The time needed to move fluid particles from the bottom to the upper layer (years) is compatible with the timing of the mini uplift.

Testing the Tourism-Led Growth hypothesis: The case of Malta

2009 ◽  
Vol 59 (3) ◽  
pp. 331-343 ◽  
Author(s):  
S. Katircioglu
Keyword(s):  
Economic Growth ◽  
Granger Causality ◽  
Relevant Literature ◽  
International Tourism ◽  
Test Results ◽  
Causality Test ◽  
Mediterranean Countries ◽  
Long Run ◽  
Equilibrium Relationship ◽  
Causality Tests

Tourism-Led Growth (TLG) hypothesis results are inconclusive for Mediterranean countries in the relevant literature. This study contributes to the literature by employing the bounds test for co-integration and Granger causality tests to investigate level relationship and the direction of causality between international tourism and economic growth in the case of Malta. Results reveal that a long-run equilibrium relationship exists between international tourism and economic growth in the case of Malta. On the other hand, Granger causality test results suggest that both the Tourism-Led Growth and output-driven tourism hypotheses can be inferred for Malta since there is bidirectional causation between international tourism and economic growth.

The 4D imaging of the source of ground deformation at Campi Flegrei caldera (southern Italy)

2012 ◽  
Vol 117 (B8) ◽  
pp. n/a-n/a ◽  
Author(s):  
Luca D'Auria ◽  
Flora Giudicepietro ◽  
Marcello Martini ◽  
Riccardo Lanari
Keyword(s):  
Southern Italy ◽  
Ground Deformation ◽  
Campi Flegrei ◽  
Campi Flegrei Caldera ◽  
4D Imaging

scholarly journals Examining the Causal Relationship between Private Sector Credit Extended and Economic Growth in Namibia

2019 ◽  
Vol 11 (2(J)) ◽  
pp. 23-29
Author(s):  
Andreas . ◽  
J P S Sheefeni
Keyword(s):  
Economic Growth ◽  
Private Sector ◽  
Granger Causality ◽  
Granger Causality Test ◽  
Test Results ◽  
Causality Test ◽  
Long Run ◽  
Integration Test ◽  
Stationarity Test ◽  
Lending Rates

The paper examined causality between Private Sector Credit Extension (PSCE) and Economic growth using quarterly data for the period 2000:Q1-2017:Q4, in Namibia. The variables employed were Gross Domestic Product (GDP), Private Sector Credit Extended, Broad Money Supply (M2) and lending rates. The study tested for stationarity in order to determine the order of integration. Furthermore, a co-integration test was conducted on different sets of variables to establish the long run relationship. Granger causality test was also conducted to establish the direction of the relationships between the variables. The results for the stationarity test showed a combination of different orders of integration. The co-integration test revealed a stable long-run relationship among the variables. The Granger causality test results revealed one-directional causality running from PSCE to GDP. Therefore, one can conclude that that change in private sector credit extended can help predict economic growth.

scholarly journals Kausalitas Ekspor Indonesia ke Tiongkok dengan Inflasi Indonesia, Suku Bunga Dasar Tiongkok, dan Nilai Tukar Indonesia

2018 ◽  
Vol 6 (4) ◽  
pp. 475-482
Author(s):  
Teddy Aldwin Leonard
Keyword(s):  
Exchange Rate ◽  
Interest Rate ◽  
Granger Causality ◽  
Inflation Rate ◽  
Granger Causality Test ◽  
Test Results ◽  
Causality Test ◽  
Causality Relationship ◽  
The Exchange Rate

Tujuan penelitian ini adalah mengetahui hubungan kausalitas antara total nilai ekspor Indonesia ke Tiongkok dengan tingkat suku bunga Tiongkok, tingkat inflasi Indonesia, dan nilai tukar Rupiah Indonesia terhadap Yuan China. Penelitian ini menggunakan uji kausalitas granger dengan variabel total nilai ekspor Indonesia ke Tiongkok, tingkat inflasi Indonesia, tingkat suku bunga dasar Tiongkok, dan nilai tukar Rupiah Indonesia terhadap Yuan China untuk melihat hubungan kausalitas antar variabel. Hasil uji kausalitas granger menunjukkan hasil bahwa total nilai ekspor Indonesia ke Tiongkok memiliki hubungan satu arah dengan variabel tingkat suku bunga Tiongkok dan variabel nilai tukar Rupiah Indonesia terhadap Yuan China, namun tidak terdapat hubungan kausalitas dengan variabel tingkat inflasi Indonesia. Hubungan satu arah antara total nilai ekspor Indonesia ke Tiongkok dengan tingkat suku bunga Tiongkok adalah total nilai ekspor Indonesia ke Tiongkok menyebabkan perubahan tingkat suku bunga Tiongkok, sedangkan hubungan satu arah antara total nilai ekspor Indonesia ke Tiongkok dengan nilai tukar Rupiah Indonesia terhadap Yuan China adalah nilai tukar Rupiah Indonesia terhadap Yuan China menyebabkan perubahan total nilai ekspor Indonesia ke Tiongkok. The purpose of this study is to know the causality relationship between the total value of Indonesia's exports to Tiongkok with Tiongkok's interest rate, the inflation rate of Indonesia, and the exchange rate of Indonesian Rupiah against the Yuan China. This study uses granger causality test with total variable of Indonesian export value to Tiongkok, Indonesia inflation rate, interest rate of Tiongkok, and Indonesian Rupiah exchange rate to Yuan China to see the relation of causality among variables. Granger causality test results show that the total value of Indonesia's export to Tiongkok has unidirectional relationship with variable of Tiongkok interest rate and variable of Indonesian Rupiah exchange rate to Yuan China, but there is no causality relationship with Indonesian inflation rate variable. The unidirectional relationship between the total value of Indonesia's exports to Tiongkok and the Tiongkok interest rate is the total value of Indonesia's exports to Tiongkok causing a change in the Tiongkok interest rate, while the unidirectional relationship between the total value of Indonesia's exports to Tiongkok and the Indonesian rupiah against the Yuan China is the value The Indonesian rupiah exchange rate against the Yuan China led to a change in the total value of Indonesia's exports to Tiongkok

scholarly journals Public Debt of Himachal Pradesh: A Granger Causality Approach

2018 ◽  
Vol 5 (01) ◽  
Author(s):  
Rakesh Kumar Pushap
Keyword(s):  
Economic Growth ◽  
Granger Causality ◽  
Public Debt ◽  
Public Expenditure ◽  
Granger Causality Test ◽  
Himachal Pradesh ◽  
Financial Indicators ◽  
Test Results ◽  
Causality Test ◽  
Tools And Techniques

The present study makes an attempt to analyse the debt position of Himachal Pradesh and discusses various issues impinging upon its growth and structure. Main objective of the study is to examine the causal relationship between public debt and financial indicators of Himachal Pradesh, i.e. economic growth (in terms of GSDP), public expenditure, revenue receipts, grant in aid and repayment of old debt. For the analysis, present study covers a period of 37 years i.e. from 1980-81 to 2016-17. Various statistical tools and techniques such as exponential growth rate, granger causality test and multiple regression have been used to carry out the analysis. Test results indicate uni-directional causality in many of the cases. Economic growth (in terms of GSDP), public expenditure, revenue receipts and grant in aid do Granger cause public debt. However, public debt does not Granger cause economic growth (in terms of GSDP), public expenditure, revenue receipts and grant in aid. Analysis also revealed the existence of feedback effect in case of causality between repayment of old debt and public debt. Lastly, economic growth (in terms of GSDP), public expenditure, grant in aid and repayment of old debt appeared as positive determinants of public debt however, revenue receipts stood as a negative determinant of public debt in Himachal Pradesh.

scholarly journals The Ground Deformation History of the Neapolitan Volcanic Area (Campi Flegrei Caldera, Somma–Vesuvius Volcano, and Ischia Island) from 20 Years of Continuous GPS Observations (2000–2019)

2021 ◽  
Vol 13 (14) ◽  
pp. 2725
Author(s):  
Prospero De Martino ◽  
Mario Dolce ◽  
Giuseppe Brandi ◽  
Giovanni Scarpato ◽  
Umberto Tammaro
Keyword(s):  
Time Series ◽  
Ground Deformation ◽  
Campi Flegrei ◽  
Volcanic Area ◽  
Campi Flegrei Caldera ◽  
Ischia Island ◽  
History Of ◽  
Continuous Gps ◽  
Gps Time Series ◽  
Gps Observations

The Neapolitan volcanic area includes three active and high-risk volcanoes: Campi Flegrei caldera, Somma–Vesuvius, and Ischia island. The Campi Flegrei volcanic area is a typical example of a resurgent caldera, characterized by intense uplift periods followed by subsidence phases (bradyseism). After about 21 years of subsidence following the 1982–1984 unrest, a new inflation period started in 2005 and, with increasing rates over time, is ongoing. The overall uplift from 2005 to December 2019 is about 65 cm. This paper provides the history of the recent Campi Flegrei caldera unrest and an overview of the ground deformation patterns of the Somma–Vesuvius and Ischia volcanoes from continuous GPS observations. In the 2000–2019 time span, the GPS time series allowed the continuous and accurate tracking of ground and seafloor deformation of the whole volcanic area. With the aim of improving the research on volcano dynamics and hazard assessment, the full dataset of the GPS time series from the Neapolitan volcanic area from January 2000 to December 2019 is presented and made available to the scientific community.

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