Seismic methods underpin many areas of NERC research; as one of a limited number of methods for "imaging" the Earth in near real time, and one of the most used methods for obtaining information about the physical properties of the subsurface. Seismic methods are used across earth and environmental sciences: for the monitoring and characterisation of earthquakes, volcanoes and landslides; for understanding impacts from human infrastructure including geothermal power and wind turbines; for the study of glacial movement, freeze-thaw processes, and permafrost behaviour; for imaging the deep Earth, including subsurface natural resources; and for animal behaviour, such as migration.

There is a growing need for rapid seismic deployments in remote, inaccessible and challenging environments, such as glacial ablation zones, where existing seismic sensors would fail. Providing access for the UK research community to such a rapid deployment seismic array is the top priority defined by the NERC Geophysical Equipment Facility (GEF) steering committee in 2021, and in the NERC Statement of Community Need it was stated that "there is an urgent requirement to replace GEF's critical backbone instrumentation with modern and forward-looking alternatives in the short term".

An array of Certimus sensors, as proposed here, would fulfil this urgent requirement by providing both critical backbone instrumentation, and bringing unique, next generation benefits, such as tilt tolerance, which has increased to plus / minus 90 degrees, from just plus / minus 2.5 degrees in older instruments. This feature is unique to the Certimus and creates a step change in world class environmental science by enabling continuous broadband seismic data acquisition in environments where other broadband seismometers would fail due to rapidly changing ground levels, such as glaciers, continental ice sheets and permafrost in the cryosphere; and areas of slope instability such as landslides and avalanches.

The Certimus uses approximately 1/3 of the power of its predecessor, which significantly reduces the number of solar panels and batteries which much be transported into the field. Additionally, smaller and lighter instruments reduce the shipping weight, which further reduces the environmental cost of data acquisition.

The array would become part of the NERC Geophysical Equipment Facility, being housed within the Leicester node (SEIS-UK) from the outset, where GEF staff would commission, support and maintain it for its entire lifespan. It would be available to UK researchers with full GEF support and training through the normal Facility application process. Demand for this class of sensor has been consistently high throughout GEF's history, often exceeding supply, and this has become an acute problem since the retirement of the older equipment.

GEF have over 20 years' experience and expertise in maintaining seismic equipment, and combined with their user training and support programs, they have demonstrated ability to keep sensors in use for over double the manufacturers' expected lifespan. Data will be archived and publically available 3 years after each loan ends, bringing additional value to this capital investment.

Our project partner has significant experience of working with the Certimus and state that they "... strongly believe that this equipment will have a transformational effect on the research undertaken by the seismology community in the UK, largely because it opens up areas of research that were not previously possible, yet sit squarely within NERC's remit". Our project partner, who has offered in-kind support to field test equipment, and train GEF staff, also believes that "access to a sizable pool of Certimus seismometers will allow the UK seismology community to stay at the forefront of its discipline for the next decade, and provide new impetus to engage in multidisciplinary research like never before".