We investigated general and physical predictors of difficult laryngeal exposure in patients undergoing suspension laryngoscopy; 93 patients were included in this prospective study. The patients were classified as difficult laryngeal exposure group or non-difficult laryngeal exposure group based on the laryngeal view in suspension laryngoscopy. Twelve parameters (age, sex, body mass index, neck circumference, full mouth opening, modified mallampati index, hyoid-mental, thyroid-mental, horizontal thyroid-mental, vertical thyroid-mental, sternum-mental distance) that could predict difficult laryngeal exposure were evaluated. Of 93 patients, 22 had difficult laryngeal exposure. Cormack-Lehane score, neck circumference, body mass index, modified mallampati index, hyoid-mental, thyroid-mental, vertical thyroid-mental, and sternum-mental distance showed significant correlation with difficult laryngeal exposure. Based on the multivariate analysis, neck circumference superior to 40 cm, hyoid-mental and sternum-mental distance with respectively a value less than 6.05 and 13.9 cm were independently associated with difficult laryngeal exposure. Muscular neck, hyoid-mental and sterno-mental distance should be considered clinical predictors of difficult laryngeal exposure. Measurements of physical variables at full extension position of the neck are more useful and reliable predictors than neutral position for the risk of difficult laryngeal exposure.

The volcanic eruption that began on 19 March 2021 at Fagradalsfjall is the first one to occur on the Reykjanes Peninsular for nearly 800 years and in Fagradalsfjall for about 6000 years. The feeder-dike was injected from a magma reservoir whose top is at about 10 km depth below the surface (but the reservoir itself reaches much greater depths). The dike formation involved at least two roof ruptures and resulting dike segments. The first occurred on 24 February and the second on 14 March 2021. The first rupture, marked by earthquakes of M2-3 close to the contact between the roof and the magma, occurred in the eastern half of the toppart of the reservoir. An injected dike segment propagated towards the surface but became arrested at the depths of 0.5-2 km. As its vertical propagation became arrested, while continuing to receive magma, the segment spread laterally, reaching an overall maximum dike strike-dimension (length) of about 10 km. The second rupture, also marked by earthquakes of M2-3, occurred about 1 km to the west of the first rupture. The injected dike segment following the second rupture eventually resulted in the dike propagating to the surface to feed the eruption which started on 19 March. We estimate the average vertical rate of the feeder-dike propagation at about 0.02 m s -1 . This is an order of magnitude lower than common rates of lateral dike propagation in rift zones, yet similar to the average rate during the Bardarbunga (Iceland) 2014 dike propagation (around 0.04 m s -1 ). The initial volcanic fissure fed by the second dike segment had a length of less than 200 m and an opening of a fraction of a metre. Subsequently, several more 'dike-fingers' reached the surface and generated volcanic fissure segments. The total length of the discontinuous, segmented fissure is many hundred metresbut only one crater is presently active. Using the aspect ratio of the fissure and basic fracture mechanics, we estimate the magmatic overpressure (driving pressure) at the beginning of the eruption as about 3 MPa. The low driving pressure and small fissure opening displacement and length are in harmony with the very low volumetric flow (effusion) rate of about 10 m 3 s -1 .

The Thrace Basin of Turkey has sandstone and carbonate reservoirs of Eocene and Oligocene age. Mapping undrained sweet spots from seismic data is currently a challenge, especially because there is no water drive after production. Time-lapse (4D) land seismic data was used to investigate undrained liquid gas pockets and to help with the planning of gas storage into the depleted reservoirs. Two vibroseis 3D baseline and monitor surveys were acquired in 2002 and 2011, respectively. The 4D seismic data has low repeatability and required conditioning to reduce the nonrepeatable 4D noise that is not related to production. Cross-equalization is applied to the base and the monitor data to bring out similarities (noise cancellation by subtracting seismic volumes), and the inverted rock properties primarily show changes due to production. We cross-equalized the corresponding angle-band stack cubes prior to prestack inversion as the available cross-equalization software was implemented for poststack seismic data. The cross-equalized angle-band stacks from the base and the monitor surveys were separately inverted to acoustic impedance (Zp), shear impedance, and density. The differences of inverted rock properties and other pore-fill indicators like Zp, P-wave velocity over S-wave velocity, and BulkRho cubes were created to map possible undrained zones after 10 years of production. A poststudy well that was drilled following the 4D analysis penetrated an undrained gas pocket.

No abstract

Although many deep-seated magma reservoirs have been detected beneath active volcanic systems in Iceland in recent decades, none were detected beneath the 5 volcanic systems on the Reykjanes Peninsula (RP) before the year 2020. This area, close to Iceland's capital Reykjavik, was subject to an unrest period with numerous earthquakes, beginning in December 2019. Using this abundant seismicity to produce tomographic images of the RP, we discovered a high Vp/Vs anomaly below the volcanic system of Fagradalsfjallthe smallest of the 5 systems on the RP. This anomaly is clear on images as early as May 2020 and we interpret it as the top part of the source reservoir of the Fagradalsfjall Volcanic System, which now supplies magma to the eruption that started there on