In November the Geological Society of London published Volume 60 in its Memoir series, with the title “The Emergence of Geophysics: A Journey into the Twentieth Century”. In his Introduction the author stipulates that he is considering developments as far as the end of the 20th century but will not venture into the 21st.
A book with the title ‘Geologic Life’, and the subtitle ‘Inhuman Intimacies and the Geophysics of Race’ has recently given rise to a considerable amount of comment on LinkedIn. What, on Earth, is it all about?
The Rio Grande Rise Massif and the Valdivia Bank have been interpreted as the two halves of an originally continuous hot-spot-related plateau formed on the Mid Atlantic Ridge. Is Iceland an example of what that plateau might have been like, geologically at least, at the time of its formation?
If it had not been for LinkedIn, I might never have been aware of the existence of the 2024 Bouguer gravity map of Brazil, and that would have been a pity. Some things jump out almost at first sight, and one of these is the narrow and almost linear gravity high that roughly coincides with the main course of the middle Amazon.
Free-air gravity maps suggest that, rather than having been a rectilinear feature, the subducted portion of the D’Entrecasteaux ridge, which impacts the Vanuatu Trench at a high angle, was curvilinear. The entire region is reminiscent, in size and the disposition of subduction -related volcanics and collision orogens, to the Banda Sea region of eastern Indonesia.
Modern airborne gravity relies largely on measurements of gravity gradients. Given how very small the signal will inevitably be, it is clear that measuring it is bound to be very, very difficult. Nevertheless, it was being done in Australia in the late 1920s with some success.