It is well established that Earth has a "Global atmospheric Electric Circuit" (GEC), through which charge separation in thunderstorms sustains large scale current flow around the planet. The GEC generates an atmospheric electric field which is present globally, and is typically 100V/m near the surface in fair weather conditions. Measurements of electric field have been shown to include information about global thunderstorm activity, local aerosol concentrations and cloud cover, as well as changes in the space weather environment. Recent work has also suggested that atmospheric electrical changes may be effective as earthquake precursors, as well as being sensitive to release of radioactivity, as evidenced by the Fukushima disaster in 2011. A current NERC Independent Research Fellowship entitled "Understanding energetic particle effects on atmospheric processes" also investigates a mechanism by which vertical current flow in the GEC can affect layer cloud microphysics, thereby providing a route by which space weather changes can alter tropospheric weather processes through atmospheric electricity. The global nature of the GEC means that in order that truly global signals are considered in understanding the processes within the circuit, many validating measurements must be made at different locations around the world. To date, no genuinely global network of FW atmospheric electricity measurements has ever existed, therefore, given the growing number of groups now involved in atmospheric electricity monitoring, such a proposal is timely. This project will bring these experts together to make the first steps towards an effective global network for FW atmospheric electricity monitoring. A specific objective of the project will be to establish the first modern archive of international FW atmospheric electric field data in close to real time to allow global studies of atmospheric electricity to be straightforwardly and robustly performed. Direct communication between network members will be facilitated by two workshops, hosted by the University of Reading towards the beginning and end of the project. The first of these will facilitate discussion of measurement practises and instrumentation, as well as establish recording and archiving procedures to archive electric field data in a standardised, easily accessible format. CEDA-BADC have agreed to support the creation of a data repository and a data manager, employed by the University of Reading, who will be responsible for liasing between CEDA-BADC and the project partners to upload data. In terms of scientific objectives, the PI will lead an investigation of space weather influences on the electric field measurements stored in the data repository. Evidence for influence from events such as solar flares, coronal mass ejections, and heliospheric current sheet crossings during the past three solar cycles will be examined using statistical techniques including super epoch analysis. During the second workshop, an outline for a peer reviewed publication describing the details of the network and data repository, as well as initial scientific findings will also be produced. This will form the basis for a joint publication from all the project partners and will help to advertise the network to the wider scientific community.

Geological dykes - sheets of rock that are often oriented vertically or steeply inclined to the bedding of preexisting rocks - typically intrude because stresses either 1) overcome rock strength or 2) exploit existing fractures created by preceding tectonic activity. Normally, it is impossible to tell these two possibilities apart because intrusion occurs along the rift zone - i.e., in the same direction as the faults within the rift. More generally, it is also poorly known how many types of fractures increase in size to form larger faults for similar reasons. Some existing mechanical models can explain how the displacements of faults scales with their length. However, they leave open questions of how fractures not showing such scaling develop. The role of pre-existing fractures in creating pathways for dyke propagation could be important for guiding the propagation. This potential "irrationality" of dyke intrusion is crucial for interpreting the nature (and source) of intense earthquake crises in volcanic systems, and ultimately for managing volcanic crises when knowledge of potential eruption sites would otherwise be an asset. For instance, if dykes are shown to preferentially follow pre-existing structural weaknesses, then detailed mapping of faults could provide important constraints for volcano eruption hazard maps and scenario-planning. An exciting opportunity to tackle this outstanding scientific problem is now presented by a rare, intense earthquake crisis in one of the most geometrically extreme, fissure-fed volcanoes on Earth, the volcanic ridge of São Jorge Island (Azores), which contains faults oblique to the rift zone. Starting on 19 March 2022, the region's seismicity levels raised extraordinarily from only 5 earthquakes recorded in 01/01-18/03, to over 27,000 M 2-3.3 events recorded from March 19th until now. Unfortunately, current earthquake locations are substantially uncertain because of geometric limitations of the existing seismic network, which includes only seismic stations in the islands. These uncertainties prevent us from relating the earthquakes to known faults and volcanic centres. Further, the limited data coverage and quality of existing networks have hindered the construction of detailed 3-D seismic tomography images of the region, with only 1-D velocity models being available based on land data. In order to address these issues, we propose to deploy a temporary seismic network of five ocean bottom seismometers (OBSs) around São Jorge and ten land broadband (BB) stations on São Jorge and surrounding islands. This will substantially enhance the region's seismic data coverage, leading to an unprecedented dataset: (1) showing how seismicity associated with a dyke intrusion relates to known faults; and (2) enabling the construction of the first detailed 3-D subsurface images of the crust and of the volcanic edifice in this rare example of a dyke in an environment with faults oblique to the rift zone. More generally, this project will bring key new insights into the structure and plumbing network of tall and narrow fissure-fed volcanic systems such as São Jorge. It will also shed new light on the mechanics of dyke intrusions and their kinematic evolution in general.