ALBERT

Description: Single rainwater samples were collected in the city of Goma (~1,1 million inhabitants), eastern Democratic Republic of the Congo, from January to June 2013 to draw a baseline for rainwater chemical composition and quality as influenced by the permanent plume of Nyiragongo volcano. This was a better period for a baseline as the neighboring Nyamulagira volcano, only 15 km apart, had no important degassing from its central crater, and hence the recorded volcanic influence on the rainwater chemistry was solely from Nyiragongo's lava lake which has been active since May 2002. The baseline for the rainwater chemistry and quality is important for this highly populated region where rainwater is the unique potable water source for the inhabitants of many villages surrounding the volcanoes, and for some of the inhabitants of the city of Goma. Our results show that samples collected at the crater rim of Nyiragongo were more acidic with pH ranging from 3.70 to 3.82, while the majority of rainwater samples collected in downtown Goma city and to the northeastern zone of the volcano had pH close to 5.7; which represents the value for rainwater from unpolluted continental areas (Berner and Berner, 2012). However, the pH was as low as 3.93 to the west of Nyiragongo volcano because the volcanic plume is directed westward by the dominant local wind direction. The western part of the city of Goma as well as the small town of Sake and many villages (e.g. Rusayo, Mubambiro, Kingi, …) are located in this zone, and experience endemic fluorosis caused by high fluoride in the available water. The mean F- in this zone was 0.38 mg/L, while the southern and northeastern zones had mean F- concentrations on 0.44 and 0.01 mg/L respectively; even though concentrations higher than the WHO guidelines were found in few samples from the western zone (1.69 mg/L) and from the southern zone (3.44 mg/L). Compared to data from Cuoco et al. (2012) obtained during the Nyamulagira 2010 eruption, and from Balagizi et al.2017 and Liotta et al., 2017 obtained during the intense degassing of both Nyiragongo and Nyamulagira lava lakes; we have noted similarity in the spatial variation of the pH, but samples from the present study showed notable lower concentrations of major elements. This is the case for fluoride which is strictly of volcanic origin. For the other major elements, anthropogenic sources, mainly the traffic and wind-blown dust; or other non-volcanic natural sources influenced their concentrations. Thus, the anions (Cl- and SO42-) and cations (Na+, K+, Mg2+, and Ca2+) from the present study are either lower compared to that previously reported in the literature for the Virunga, or are both comparable for the zones impacted by anthropogenic activities.

Description: Published

Description: 130859

Description: 6A. Geochimica per l'ambiente e geologia medica

Description: JCR Journal

Description: We address the potential for methane to exist in the subsurface of Mars, focusing on its generation, accumulation in sealed traps, and seepage to the atmosphere. We discuss two abiotic processes that could have produced subsurface methane, even if life never developed on the planet. Compared to Earth, accumulations of methane on Mars are likely to be limited, and those that are present may be better sealed by the thick and planetwide cryosphere. Releases are thus expected to be minor and episodic. We emphasize the importance of long-term, continuous monitoring of predicted release sites, as limited, episodic releases could be easy to miss. Moreover, we note that numerous scenarios of methane fluxes from terrestrial analogs may explain non-detections by the ExoMars Trace Gas Orbiter (TGO), as they can produce atmospheric concentrations below the TGO limit of detection. Our work does not negate the potential for meteoric/cometary sources of methane, but it does illustrate the strength of the case for subsurface sourcing. Finally, we provide a map of potential locations of release and discuss remaining uncertainties and a path forward.

Description: Published

Description: 149-174

Description: 6A. Geochimica per l'ambiente e geologia medica

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Arenas Gómez, Claudia M., Sabin, K. Z., & Echeverri, K. Wound healing across the animal kingdom: Crosstalk between the immune system and the extracellular matrix. Developmental Dynamics, (2020): 1-13, doi:10.1002/dvdy.178.

Description: Tissue regeneration is widespread in the animal kingdom. To date, key roles for different molecular and cellular programs in regeneration have been described, but the ultimate blueprint for this talent remains elusive. In animals capable of tissue regeneration, one of the most crucial stages is wound healing, whose main goal is to close the wound and prevent infection. In this stage, it is necessary to avoid scar formation to facilitate the activation of the immune system and remodeling of the extracellular matrix, key factors in promoting tissue regeneration. In this review, we will discuss the current state of knowledge regarding the role of the immune system and the interplay with the extracellular matrix to trigger a regenerative response.

Description: The research in the Echeverri lab is supported NIH NCID R01 to Karen Echeverri and start‐up funds from the MBL. Keith Z. Sabin has been supported by an NIH T32 GM113846 grant.

Description: Author Posting. © American Geophysical Union, 2020. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 125(9), (2020): e2019JC015269, doi:10.1029/2019JC015269

Description: Wave‐supported fluid mud (WSFM) plays an important role in sediment downslope transport on the continental shelves. In this study, we incorporated WSFM processes in the wave boundary layer (WBL) into the Community Sediment Transport Modeling System (CSTMS) on the platform of the Coupled Ocean‐Atmosphere‐Wave‐and‐Sediment Transport modeling system (COAWST). The WSFM module was introduced between the bottommost water layer and top sediment layer, which accounted for the key sediment exchange processes (e.g., resuspension, vertical settling, diffusion, and horizontal advection) at the water‐WBL and WBL‐sediment bed boundaries. To test its robustness, we adapted the updated model (CSTMS + WBL) to the Atchafalaya shelf in the northern Gulf of Mexico and successfully reproduced the sediment dynamics in March 2008, when active WSFM processes were reported. Compared with original CSTMS results, including WSFM module weakened the overall intensity of sediment resuspension, and the CSTMS + WBL model simulated a lutocline between the WBL and overlying water due to the formation of WSFM. Downslope WSFM transport resulted in offshore deposition (〉4 cm), which greatly changed the net erosion/deposition pattern on the inner shelf off the Chenier Plain. WSFM flux was comparable with suspended sediment flux (SSF) off the Atchafalaya Bay, and it peaked along the Chenier Plain coast where wave activities were strong and the bathymetric slope was steep. The influence of fluvial sediment supply on sediment dynamics was limited in the Atchafalaya Bay. Sensitivity tests of free settling, flocculation, and hindered settling effects suggested that sediments were transported further offshore due to reduced settling velocity in the WBL once fluid mud was formed. Although sediment concentration in the WBL was sensitive to surface sediment critical shear stress, cohesive bed behavior was less important in WSFM dynamics when compared with strong hydrodynamic during cold fronts.

Description: Research support provided through NSF CyberSEES (Award CCF‐1856359), NASA (Award NNH17ZHA002C), Louisiana Board of Regents (award number NASA/LEQSF(2018‐20)‐Phase3‐11), Bureau of Ocean Energy Management (Cooperative Agreement Award M20AC00007), NSF Coastal SEES (Award EAR‐1427389 ), NSF (Award OCE‐20203676), and LSU Foundation Billy and Ann Harrison Endowment for Sedimentary Geology.

Description: 2021-02-19

Description: In this paper, we study the spatial distribution and temporal evolution of the postseismic deformation of the 2010–2011 Rigan earthquake sequence which occurred at the southern termination of the East Lut fault system, southeast Iran. One-year GPS measurements after the Rigan earthquake sequence reveals right-lateral postseismic displacement along the East Chahqanbar fault and left-lateral postseismic displacement along the South Chahqanbar fault. To investigate the deformation variations in time and space, InSAR time-series of COSMO-SkyMed images is applied using the Small Baseline Subset algorithm. The results confirm a clear cumulative postseismic signal increasing to 8 mm during the first five months following the first mainshock in the direction of the coseismic displacement. The cumulative postseismic displacements are well correlated with the cumulative number of the aftershocks and their associated moment release. Considering this correlation and the observation of a sharp discontinuity along the coseismic fault in the displacement map, it is concluded that the after-slip mechanism is responsible for the observed postseismic deformation in the study region. This study is the first observation of a short-term postseismic motion in eastern Iran through geodetic data in contrast with long-lasting postseismic displacements following the earthquakes that occurred around Lut block. Modeling of the postseismic displacement results in a distributed slip pattern with a maximum slip of 0.8 m on the fault plane responsible for the 2010 Rigan coseismic deformation. This indicates that the postseismic deformation on barriers remained unbroken during the mainshock.

Description: Published

Description: 228630

Description: 2T. Deformazione crostale attiva

Description: JCR Journal