Trade-offs in moving citizen-based anuran call surveys online during the SARS-CoV-2 pandemic: Lessons from rural Appalachia, USA.

Citizen science approaches provide adaptable methodologies for enhancing the natural history knowledge of understudied taxa and engaging underserved populations with biodiversity. However, transitions to remote, virtual training, and participant recruitment in response to public health crises like the SARS-CoV-2 pandemic have the potential to disrupt citizen science projects. We present a comparison of outputs from a citizen science initiative built around call surveys for the Mountain Chorus Frog (), an understudied anuran, in Appalachian Virginia, USA, prior to and during the SARS-CoV-2 pandemic.

Marine geophysics. New global marine gravity model from CryoSat-2 and Jason-1 reveals buried tectonic structure.

Gravity models are powerful tools for mapping tectonic structures, especially in the deep ocean basins where the topography remains unmapped by ships or is buried by thick sediment. We combined new radar altimeter measurements from satellites CryoSat-2 and Jason-1 with existing data to construct a global marine gravity model that is two times more accurate than previous models. We found an extinct spreading ridge in the Gulf of Mexico, a major propagating rift in the South Atlantic Ocean, abyssal hill fabric on slow-spreading ridges, and thousands of previously uncharted seamounts.

Mapping amphibian contact zones and phylogeographical break hotspots across the United States.

Identifying congruence in the geographical position of lineage breaks and species range limits across multiple taxa is a focus of the field of comparative phylogeography. These regions are biogeographical hotspots for investigations into the processes driving divergence at multiple phylogenetic levels. We used spatially explicit statistical methods to identify these regions for amphibians across the United States.

How supercontinents and superoceans affect seafloor roughness.

Seafloor roughness varies considerably across the world's ocean basins and is fundamental to controlling the circulation and mixing of heat in the ocean and dissipating eddy kinetic energy. Models derived from analyses of active mid-ocean ridges suggest that ocean floor roughness depends on seafloor spreading rates, with rougher basement forming below a half-spreading rate threshold of 30-35 mm yr(-1) (refs 4, 5), as well as on the local interaction of mid-ocean ridges with mantle plumes or cold-spots. Here we present a global analysis of marine gravity-derived roughness, sediment thickness, seafloor isochrons and palaeo-spreading rates of Cretaceous to Cenozoic ridge flanks.