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"Roman, Diana"
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Deep Long‐Period Earthquakes at Akutan Volcano From 2005 to 2017 Better Track Magma Influxes Compared to Volcano‐Tectonic Earthquakes
by
Roman, Diana C.
,
Song, Zilin
,
Tan, Yen Joe
in
Deep long‐period earthquakes
,
Earthquake prediction
,
Earthquake swarms
2023
Both volcano‐tectonic (VTs) and deep long‐period earthquakes (DLPs) have been documented at Akutan Volcano, Alaska and may reflect different active processes helpful for eruption forecasting. In this study, we perform high‐resolution earthquake detection, classification, and relocation using seismic data from 2005 to 2017 to investigate their relationship with underlying magmatic processes. We find that the 2,787 VTs and 787 DLPs are concentrated above and below the inferred magma reservoir respectively. They both are clustered as swarms and occur preferentially during inflation episodes with no spatial migrations. However, moment release rates of DLP swarms show a stronger correlation with inflation and their low‐frequency content is likely a source instead of a path effect. Therefore, we infer that DLPs are directly related to unsteady magma movement through a complex pathway. In comparison, repeating events are observed in VTs. Thus, we conclude that they represent fault rupture triggered by magma/fluid movement or larger earthquakes. Plain Language Summary Volcano eruption forecasting is a challenging task that often requires the deciphering of processes underlying observed signs of volcanic unrest. As seismometers become common monitoring sensors on volcanoes, the recorded ground motion is valuable for scientists to study eruption precursors. Earthquakes are commonly observed and generally inferred to be associated with stress perturbations in the shallow crust. However, earthquakes with predominantly lower‐frequency energy are sometimes observed at depth and their origin is enigmatic. In this paper, we use the existing catalog of earthquakes at Akutan Volcano in Alaska between 2005 and 2017 as templates to successfully detect more earthquakes before locating them with higher precision. We find that earthquakes at Akutan Volcano tend to occur in swarms during times when the ground inflates due to magma accumulation beneath the volcano. Some earthquakes have predominantly low‐frequency energy which suggests a different source mechanism compared to regular earthquakes. Furthermore, the largest events are more strongly correlated with surface inflation. Therefore, we conclude that these lower‐frequency earthquakes are more directly related to unsteady magma movement through a complex pathway compared to regular earthquakes which represent fault rupture triggered by magma/fluid movement or larger earthquakes. Key Points Moment release rates of deep long‐period events correlate more strongly with inflation episodes compared to volcano‐tectonic events Akutan deep long‐period earthquakes are likely due to non‐stationary source effects like unsteady magma transport through complex pathways Akutan volcano‐tectonic earthquakes represent fault ruptures triggered by magma/fluid movements or larger earthquakes
Journal Article
Double Reservoirs Imaged Below Great Sitkin Volcano, Alaska, Explain the Migration of Volcanic Seismicity
2023
Volcanic seismicity provides essential insights into the behavior of an active volcano across multiple time scales. However, to understand how magma moves as the eruption cycle develops, better knowledge of the geometry and physical properties of the magma plumbing system is required. In this study, using full‐wave ambient noise tomography, we image the three‐dimensional (3‐D) crustal shear‐wave velocity structure below Great Sitkin Volcano in the central Aleutian Arc. The velocity model reveals two low‐velocity anomalies correlating with the migration of volcanic seismicity. With a bulk melt fraction of about 2.5%–9%, these low‐velocity anomalies are interpreted as mushy magma reservoirs. We propose a six‐stage eruption cycle to explain the migration of seismicity and the alternating eruption of the two reservoirs with different recharging histories. These findings have broad implications for the dynamics of magma plumbing systems and the structural control of eruption behaviors. Plain Language Summary Understanding magma accumulation and transport systems below active volcanoes is essential for predicting eruption behavior and assessing the potential hazards. The distribution of earthquakes can partly be used to infer the development of magmatic activity at different times. However, to understand how magma moves at different stages of an eruption cycle, better knowledge of what the magma plumbing system looks like is necessary. In this study, we use an advanced seismic imaging method to construct the 3‐D crustal shear‐wave velocity structure below Great Sitkin Volcano in the central Aleutian Arc. The velocity model reveals two crustal magma reservoirs, which correlate with the migration of seismicity. We propose a six‐stage eruption cycle to explain the evolution of seismicity in space and time across the island and the alternating eruption of two reservoirs. The findings in this study help to understand better the control of eruption behaviors by the underlying magma plumbing system at active volcanoes. Key Points The pre‐ and co‐eruptive seismicity below Great Sitkin Volcano, Alaska, shows a spatiotemporal migration A new 3‐D shear‐wave velocity model reveals two crustal low‐velocity anomalies that correlate with the migrating seismicity We propose a six‐stage eruption cycle involving two magma reservoirs to explain the long‐term and short‐term seismicity patterns
Journal Article
Sustained Co‐Eruptive Increase in Seismic Velocity Below Great Sitkin Volcano Due To Magma Extrusion
by
Roman, Diana C.
,
Haney, Matthew
,
Yang, Xiaotao
in
Active control
,
Aleutian volcanoes
,
Ambient noise
2024
Volcanic eruptions carry essential information on the dynamics of volcanic systems. Studies have documented variable eruption styles and eruptive surface deformation. However, co‐eruptive subsurface structural changes remain poorly understood. Here we characterize the seismic velocity changes from July 2019 to July 2023 at Great Sitkin Volcano in the central Aleutian volcanic arc, using single‐station ambient noise interferometry at five three‐component seismic stations. Coincident with the lava effusion since late July 2021, about two months after the explosive eruption on 26 May 2021, we observe a sustained velocity increase, most prominently to the northwest of the caldera. We attribute this velocity increase to the structural changes with magma extrusion, with the spatial variation controlled by the geometry of the magma system or the property of shallow volcaniclastics. Our findings offer insights into understanding co‐eruptive structural modifications at active volcanoes. Plain Language Summary Volcanic eruptions provide important insights into how volcanoes work and the potential risks they pose. This study looks at the ongoing eruption at Great Sitkin Volcano in the central Aleutian volcanic arc to better understand the changes happening beneath the surface. We measure the changes in the velocity of seismic waves, with data from five seismometers on the island. We collected data from July 2019 to July 2023, covering different eruptive stages and multiple lava effusion episodes during the eruption that started on 26 May 2021. Coincident with the lava effusion since late July 2021, we notice a significant increase in seismic velocities, most prominently at a station northwest of the volcano's central crater. We conclude that this increase reflects the structural change in the shallow subsurface due to magma extrusion, with deflation of the edifice and closure of cracks. The findings in this study help to improve our understanding of how volcanoes behave during eruptions. Key Points We observe prominent, spatially variable increases in seismic velocity during lava effusions at Great Sitkin Volcano since late July 2021 The sustained co‐eruptive increase in seismic velocity reflects structural changes with crack closures as the consequence of magma extrusion The distinct spatial variation of the velocity increase may be controlled by reservoir geometry or the strength of shallow volcaniclastics
Journal Article
Rheumatoid arthritis-related interstitial lung disease (RA-ILD): methotrexate and the severity of lung disease are associated to prognosis
by
Herrera-Bringas, Denisse
,
Mateos-Toledo, Heidegger
,
Pérez-Dorame, Renzo
in
Adult
,
Aged
,
Antirheumatic Agents - therapeutic use
2017
Interstitial lung disease (ILD) is a severe rheumatoid arthritis (RA) manifestation. The worst survival has been associated with usual interstitial pneumonia (UIP) definitive pattern in high-resolution chest tomography (HRCT) scans. Moreover, the use of methotrexate in RA-ILD is controversial. Our aim was to evaluate prognostic factors including methotrexate in an RA-ILD cohort and their association with survival. RA-ILD patients referred for medical evaluation and treatment at a single center were included. At the baseline, pulmonary function tests were carried out and a HRCT was obtained. A radiologist evaluated the ILD tomographic pattern and the extent of lung disease. Patients were considered as receiving methotrexate therapy if this drug was specifically prescribed for the treatment of RA-ILD at the beginning of follow up. Seventy-eight patients were included. UIP definite pattern in HRCT was not associated to worse survival. Variables associated with mortality reflected the severity of lung disease. Treatment with methotrexate was associated with survival (HR 0.13, 95% CI 0.02–0.64); older patients had worse prognosis (HR 1.04, 95% CI 1.003–1.09). After adjusting for confounding variables, methotrexate was strongly associated with survival. Methotrexate treatment during follow up was associated with survival. The severity of lung disease and not the tomographic pattern is associated with mortality; older patients had worse prognosis.
Journal Article
Ergodic seismic precursors and transfer learning for short term eruption forecasting at data scarce volcanoes
by
Miller, Craig
,
Caudron, Corentin
,
Contreras-Arratia, Rodrigo
in
704/2151/2809
,
704/2151/598
,
704/4111
2025
Abstract Seismic data recorded before volcanic eruptions provides important clues for forecasting. However, limited monitoring histories and infrequent eruptions restrict the data available for training forecasting models. We propose a transfer machine learning approach that identifies eruption precursors signals that consistently change before eruptions across multiple volcanoes. Using seismic data from 41 eruptions at 24 volcanoes over 73 years, our approach forecasts eruptions at unobserved (out-of-sample) volcanoes. Tested without data from the target volcano, the model demonstrated accuracy comparable to direct training on the target and exceeded benchmarks based on seismic amplitude. These results indicate that eruption precursors exhibit ergodicity, sharing common patterns that allow observations from one group of volcanoes to approximate the behavior of others. This approach addresses data limitations at individual sites and provides a useful tool to support monitoring efforts at volcano observatories, improving the ability to forecast eruptions and mitigate volcanic risks.
Journal Article
Aseismic mid-crustal magma reservoir at Cleveland Volcano imaged through novel receiver function analyses
by
Roman, Diana C.
,
Wagner, Lara S.
,
Janiszewski, Helen A.
in
704/2151/508
,
704/2151/598
,
Humanities and Social Sciences
2020
Processes related to eruptions at arc volcanoes are linked by structures that transect the entire crust. Imaging the mid- to lower-crustal portions (here, ~5–15 km and >15 km respectively) of these magmatic systems where intermediate storage may occur has been a longstanding challenge. Tomography, local seismic source studies, geodetic, and geochemical constraints, are typically most sensitive to shallow (<5 km) storage and/or have insufficient resolution at these depths. Geophysical methods are even further limited at frequently-erupting volcanoes where well-developed trans-crustal magmatic systems are likely to exist, due to a lack of deep seismicity. Here we show direct evidence for mid-crustal magma storage beneath the frequently erupting Cleveland volcano, Alaska, using a novel application of seismic receiver functions. We use P-s scattered waves from the Moho as virtual sources to investigate S-wave velocities between the Moho and the surface. Our forward modeling approach allows us to provide direct constraints on the geometry of low velocity regions beneath volcanoes despite having a comparatively sparse seismic network. Our results show clear evidence of mid-crustal magma storage beneath the depths of located volcanic seismicity. Future work using similar approaches will enable an unprecedented comparative examination of magmatic systems beneath sparsely instrumented volcanoes globally.
Journal Article
Failed magmatic eruptions: late-stage cessation of magma ascent
by
Roman, Diana C.
,
Moran, Seth C.
,
Newhall, Chris
in
Degassing
,
Earth and Environmental Science
,
Earth Sciences
2011
When a volcano becomes restless, a primary question is whether the unrest will lead to an eruption. Here we recognize four possible outcomes of a magmatic intrusion: “deep intrusion”, “shallow intrusion”, “sluggish/viscous magmatic eruption”, and “rapid, often explosive magmatic eruption”. We define “failed eruptions” as instances in which magma reaches but does not pass the “shallow intrusion” stage, i.e., when magma gets close to, but does not reach, the surface. Competing factors act to promote or hinder the eventual eruption of a magma intrusion. Fresh intrusion from depth, high magma gas content, rapid ascent rates that leave little time for enroute degassing, opening of pathways, and sudden decompression near the surface all act to promote eruption, whereas decreased magma supply from depth, slow ascent, significant enroute degassing and associated increases in viscosity, and impingement on structural barriers all act to hinder eruption. All of these factors interact in complex ways with variable results, but often cause magma to stall at some depth before reaching the surface. Although certain precursory phenomena, such as rapidly escalating seismic swarms or rates of degassing or deformation, are good indicators that an eruption is likely, such phenomena have also been observed in association with intrusions that have ultimately failed to erupt. A perpetual difficulty with quantifying the probability of eruption is a lack of data, particularly on instances of failed eruptions. This difficulty is being addressed in part through the WOVOdat database. Papers in this volume will be an additional resource for scientists grappling with the issue of whether or not an episode of unrest will lead to a magmatic eruption.
Journal Article
Evaluation of the Aquatic Toxicity of Several Triazole Fungicides
by
Isvoran, Adriana
,
Roman, Diana-Larisa
,
Boros, Bianca-Vanesa
in
Aquatic ecosystems
,
Aquatic environment
,
Aquatic organisms
2024
Fungicides play an important role in crop protection, but they have also been shown to adversely affect non-target organisms, including those living in the aquatic environment. The aim of the present study is to combine experimental and computational approaches to evaluate the effects of flutriafol, metconazole, myclobutanil, tebuconazole, tetraconazole and triticonazole on aquatic model organisms and to obtain information on the effects of these fungicides on Lemna minor, a freshwater plant, at the molecular level. The EC50 (the half-maximum effective concentration) values for the growth inhibition of Lemna minor in the presence of the investigated fungicides show that metconazole (EC50 = 0.132 mg/L) and tetraconazole (EC50 = 0.539 mg/L) are highly toxic, tebuconazole (EC50 = 1.552 mg/L), flutriafol (EC50 = 3.428 mg/L) and myclobutanil (EC50 = 9.134 mg/L) are moderately toxic, and triticonazole (EC50 = 11.631 mg/L) is slightly toxic to this plant. The results obtained with the computational tools TEST, ADMETLab2.0 and admetSAR2.0 also show that metconazole and tetraconazole are toxic to other aquatic organisms: Pimephales promelas, Daphnia magna and Tetrahymena pyriformis. A molecular docking study shows that triazole fungicides can affect photosynthesis in Lemna minor because they strongly bind to C43 (binding energies between −7.44 kcal/mol and −7.99 kcal/mol) and C47 proteins (binding energies between −7.44 kcal/mol and −8.28 kcal/mol) in the reaction center of photosystem II, inhibiting the binding of chlorophyll a to these enzymes. In addition, they can also inhibit glutathione S-transferase, an enzyme involved in the cellular detoxification of Lemna minor.
Journal Article
Rheumatoid arthritis-related interstitial lung disease (RA-ILD): a possible association between disease activity and prognosis
by
Herrera-Bringas, Denisse
,
Mateos-Toledo, Heidegger
,
Pérez-Dorame, Renzo
in
Clinical trials
,
Hypotheses
,
Lung diseases
2022
Objectives
We hypothesized that RA disease activity might be associated with the survival of RA-ILD patients. To evaluate this possibility, we analyzed data on disease activity during follow-up in an RA-ILD cohort and compared disease activity between surviving patients and those who died during follow-up.
Methods
RA-ILD patients referred for medical evaluation and treatment at a single center, with CDAI scores during all follow up were included. We estimated the HR of the mean of the CDAI score during follow-up with survival. Also, we compared the survival function of patients with high disease activity (CDAI scores ≥ 22) during all follow-up with those with moderate and low disease activity.
Results
Thirty-seven patients were included. The mean of the CDAI score during follow-up was higher in death patients (median 30.8 ± 18.5 Vs. 16.8 ± 11.3), and a single unit increase in the mean of the CDAI score was associated with non-survival, HR:1.07 (95% CI: 1.02 -1.12). Patients with high disease activity during all follow-up (CDAI scores > 22) had lower survival function in comparison with moderate and low disease activity (P = 0.042).
Conclusion
The results of the study suggest that higher RA disease activity is associated with a worse prognosis of RA-ILD patients. The hypothesis that high disease activity is associated with worse survival in RA-ILD patients must be evaluated in more extensive cohort studies and clinical trials.
Key Points:
• RA-ILD patients with high disease activity during follow-up had a worse prognosis than those with moderate or low disease activity.
• The study results suggest the hypothesis that patients with RA-ILD must be treated with a treat to target strategy, with the aim of remission or low RA disease activity.
Journal Article
Computational Assessment of Pharmacokinetics and Biological Effects of Some Anabolic and Androgen Steroids
2018
PurposeThe aim of this study is to use computational approaches to predict the ADME-Tox profiles, pharmacokinetics, molecular targets, biological activity spectra and side/toxic effects of 31 anabolic and androgen steroids in humans.MethodsThe following computational tools are used: (i) FAFDrugs4, SwissADME and admetSARfor obtaining the ADME-Tox profiles and for predicting pharmacokinetics;(ii) SwissTargetPrediction and PASS online for predicting the molecular targets and biological activities; (iii) PASS online, Toxtree, admetSAR and Endocrine Disruptomefor envisaging the specific toxicities; (iv) SwissDock to assess the interactions of investigated steroids with cytochromes involved in drugs metabolism.ResultsInvestigated steroids usually reveal a high gastrointestinal absorption and a good oral bioavailability, may inhibit someof the human cytochromes involved in the metabolism of xenobiotics (CYP2C9 being the most affected) and reflect a good capacity for skin penetration. There are predicted numerous side effects of investigated steroids in humans: genotoxic carcinogenicity, hepatotoxicity, cardiovascular, hematotoxic and genitourinary effects, dermal irritations, endocrine disruption and reproductive dysfunction.ConclusionsThese results are important to be known as an occupational exposure to anabolic and androgenic steroids at workplaces may occur and because there also is a deliberate human exposure to steroids for their performance enhancement and anti-aging properties.
Journal Article