Magma emission rates fromshallow submarine eruptions using airborne thermal imaging

The effusion rate is the most important parameter to gatherwhen a volcanic eruption occurs, because it controls the way inwhich a lava body grows, extends and expands, influencing its dimensional properties. Calculation of lava flow volume from thermal images collected by helicopter surveys has been largely used during the last decade for monitoring subaerial effusive eruptions. However, due to the depths where volcanic activity occurs, monitoring submarine volcanic eruptions is a very difficult task. The 2011–2012 submarine volcanic eruption at El Hierro, Canary Islands, has provided a unique and excellent opportunity to monitor eruptive processes occurring on the seabed. The use of a hand-held thermal camera during daily helicopter flights allowed us to estimate for the first time the daily and total erupted magma volumes from a submarine eruption. The volume of magma emitted during this eruption has been estimated at 300 Mm3, giving an average effusion rate of ~25 m3 s−1. Thermal imagery by helicopter proved to be a fast, inexpensive, safe and reliable technique of monitoring volcanic eruptions when they occur on the shallow seabed.This research was financially supported by the projects MAKAVOL (MAC/3/C161) from the European Union MAC 2007–2013 Transnational Cooperation Program as well as from the Cabildo Insular de Tenerife. We are also grateful to the staff of El Hierro airport (AENA) for providing logistical support.Published219-2255V. Sorveglianza vulcanica ed emergenzeJCR Journalrestricte

The first period of the 2002 Etna eruption (27 October-5 November): preliminary results

We report on the first period of the 2002 Etna eruption started on 27th October and ended on 5th November, occurring 15 months after the end of the 2001 eruption. Volcanological and geochemical data are presented in order to characterize the complex intrusion mechanism that contemporaneously involved the NE and S flanks of the volcano. Preliminary data outline that two distinct magma intrusions fed the eruptive fissures. Strong fire fountain activity mainly from the S fissure, produced copious ash fall in eastern Sicily, causing prolonged closure of Catania and Reggio Calabria airports. Lava emitted from the NE fissure formed a 6.2 km long lava flow field that destroyed the tourist facilities of Piano Provenzana area and part of Linguaglossa pine forest.Published1-10reserve

Reconstruction of the eruptive activity on the NE sector of Stromboli volcano: timing of flank eruptions since 15 ka

A multidisciplinary geological and compositional investigation allowed us to reconstruct the occurrence of flank eruptions on the lower NE flank of Stromboli volcano since 15 ka. The oldest flank eruption recognised is Roisa, which occurred at ~15 ka during the Vancori period, and has transitional compositional characteristics between the Vancori and Neostromboli phases. Roisa was followed by the San Vincenzo eruption that took place at ~12 ka during the early stage of Neostromboli period. The eruptive fissure of San Vincenzo gave rise to a large scoria cone located below the village of Stromboli, and generated a lava flow, most of which lies below sea level. Most of the flank eruptions outside the barren Sciara del Fuoco occurred in a short time, between ~9 and 7 ka during the Neostromboli period, when six eruptive events produced scoria cones, spatter ramparts and lava flows. The Neostromboli products belong to a potassic series (KS), and cluster in two differently evolved groups. After an eruptive pause of ~5,000 years, the most recent flank eruption involving the NE sector of the island occurred during the Recent Stromboli period with the formation of the large, highly K calc-alkaline lava flow field, named San Bartolo. The trend of eruptive fissures since 15 ka ranges from N30°E to N55°E, and corresponds to the magma intrusions radiating from the main feeding system of the volcano

Mammalian sex determination—insights from humans and mice

Disorders of sex development (DSD) are congenital conditions in which the development of chromosomal, gonadal, or anatomical sex is atypical. Many of the genes required for gonad development have been identified by analysis of DSD patients. However, the use of knockout and transgenic mouse strains have contributed enormously to the study of gonad gene function and interactions within the development network. Although the genetic basis of mammalian sex determination and differentiation has advanced considerably in recent years, a majority of 46,XY gonadal dysgenesis patients still cannot be provided with an accurate diagnosis. Some of these unexplained DSD cases may be due to mutations in novel DSD genes or genomic rearrangements affecting regulatory regions that lead to atypical gene expression. Here, we review our current knowledge of mammalian sex determination drawing on insights from human DSD patients and mouse models

Spatial variations in lava flow field thermal structure and effusion rate derived from very high spatial resolution hyperspectral (MIVIS) data

High spatial resolution hyperspectral measurements of volcanic thermal anomalies allow for an unconstrained solution of a two-component thermal model. This can be used for identification of lava flow emplacement style and the calculation of lava flow heat and volume flux. The multispectral infrared and visible imaging spectrometer (MIVIS) is an airborne sensor equipped with 72 bands in the short infrared range and 10 bands in the thermal infrared region of the spectrum. We used MIVIS acquired for Mount Etna (Italy) during the July–August 2001 eruption to solve the dual band equations in an unconstrained fashion using three bands of unsaturated data. Our results suggest a complex thermal structure for Etnean lava flows. This is characterized by a downflow transition from a lightly crusted active channel to a more heavily crusted distal section, both surrounded by zones of stagnant cooling flow where exposed molten material is absent and maximum temperatures are thus lower. The total flow field effusion rate obtained for 29 July 2001 (0700 local time) of 8–16 m3/s is in excellent agreement with that obtained from ground-based measurements and Advanced Very High Resolution Radiometer data. Flow-by-flow effusion rates obtained from the MIVIS data vary depending on whether the vent is linked to the central conduit or the dyke that was injected from greater depth, as well as vent elevation, with lower elevation vents experiencing higher effusion rates