Explosion-generated infrasound recorded on ground and airborne microbarometers at regional distances

Recent work in deploying infrasound (low-frequency sound) sensors on aerostats and free-flying balloons has shown them to be viable alternatives to ground stations. However, no study to date has compared the performance of surface and freefloating infrasound microbarometers with respect to acoustic events at regional (100s of kilometers) range. The prospect of enhanced detection of aerial explosions at similar ranges, such as those from bolides, has not been investigated either. We examined infrasound signals from three 1-ton trinitrotoluene (TNT) equivalent chemical explosions using microbarometers on two separate balloons at 280- to 400-km ranges and ground stations at 6.3- to 350-km ranges. Signal celerities were consistent with acoustic waves traveling in the stratospheric duct. However, significant differences were noted between the observed arrival patterns and those predicted by an acoustic propagation model. Very low-background noise levels on the balloons were consistent with previous studies that suggest wind interference is minimal on freely drifting sensors. Simulated propagation patterns and observed noise levels also confirm that balloon-borne microbarometers should be very effective at detecting explosions in the middle and upper atmosphere as well as those on the surface

Bulk organic δ13C and C/N ratios as palaeosalinity indicators within a Scottish isolation basin.

Microfossils in isolation basin sediments are frequently used to reconstruct sea-level change, but preservation problems and non-analogue situations can limit their usefulness. Here we investigate the potential of stable carbon isotopes (δ13C) and C/N ratios from bulk organic matter, as an alternative proxy of salinity within isolation basin sediments from a basin in northwest Scotland. Within the Holocene sediment δ13C and C/N are determined largely by the mean weighted values of the predominant source of the organic material. Analysis of modern materials and comparison with the diatom record shows that the marine parts of the sequence are dominated by high δ13C and variable C/N. In the fresh water sequences the organic material is a mixture of both freshwater aquatic and terrestrial plant input that have relatively low δ13C and high C/N. The application of δ13C and C/N ratios in the studied basin in general follow the environmental change recorded by the diatoms and shows the potential of bulk organic matter in the investigation of salinity change in isolation basins

UK Geoenergy Observatories, Glasgow Environmental Baseline Surface Water Chemistry Dataset 1

This report accompanies the United Kingdom Geoenergy Observatories Glasgow Surface Water Chemistry Dataset_1. The dataset comprises chemical analysis of 98 (84 samples and 14 duplicates) surface water samples that were collected monthly between February 2019 and March 2020 from water bodies proximal to the Glasgow Observatory. This baseline dataset provides valuable information on surface water chemistry prior to the operation of the Observatory, against which any future change can be assessed. This information is necessary to help understand the Observatory hydrological-hydrogeological regime; and to help de-risk similar shallow geothermal schemes in the future, provide public reassurance, and inform sustainable energy policy