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Science (mostly history, and mostly gravity)

Chasing the history of the gravity method sometimes took me down side-tracks that did not quite fit the theme, and so never made it into ‘The Hunt’. Also, and inevitably, there were stories that should have been in ‘The Hunt’ but which I missed. Here are some of them, and bits of new Earth Science are sometimes included!

IGCP 710 and the case for a new PANCARDI

In the late 1990s the European Science Foundation, taking advantage of the new possibilities for scientific interchange and fieldwork in a Europe no longer divided by an Iron Curtain, sponsored an international programme known as PANCARDI within which geologists and geophysicists from the countries of the Carpathian and Dinaric orogens and the Pannonian Basin came together to exchange information and reach a better understanding of the evolution through time of that very complex region. Is it not time for a second such programme?

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More on Myanmar

Most of Myanmar considered prospective for hydrocarbons was covered by gravity surveys between 1964 and 1975. The results have been published as small-scale contour maps, but with gravity values referred to an arbitrary datum; there are also significant errors and ambiguities in the contouring. An approximate transfer to the current international IGSN71 system has proved possible, but correction of the contouring errors will not be possible without access to the underlying data.

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The magnetics of Seram

The presence of ultramafic rocks on the eastern Indonesian islands of Ambon and Seram has been known since the work of the early Dutch geologists in the East Indies. Have geophysical potential-field data anything to contribute to understanding their distribution and emplacement history?

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Before longitude

In her best-selling book  Longitude, Dava Sobell told the story of the ultimately successful efforts made in the England of the first half of the Eighteenth Century to measure longitude at sea using very accurate clocks, and also mentioned that attempts had been made in the second half of the Seventeenth Century to do the same thing. Christiaan Huygens figured prominently in the account but there is much more to that part of the story than appeared in the book. It began with an obscure Scottish nobleman.

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The perils of processing gravity data

LinkedIn is full of people claiming that just because their opinions conflict with the those of the majority, that does not mean they are wrong. No quarrel with that, but problems arise when they reverse the argument and claim that it somehow proves they are right. When, in doing so, they wander into areas about which I think I know something, I have to protest. And increasingly I see that happening when gravity is being used to investigate geology.

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The perils of big gravity data

According to NASA, the new Earth Gravity Model EGM2020, although not yet released, has been completed, .It will be based on a great deal of new data and will be a valuable addition for regional studies. But, like its predecessors, there is a danger that it will be misused.

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The break-up of the Banda slab

Plots of earthquake hypocentres on north-south swathes across the Banda Sea show that the northern and southern Wadati-Benioff Zones zones involve the same slab of subducted lithosphere. But can that scoop-shaped slab hang together?

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Tomography and the Molucca Sea

Improvements in seismic tomography have allowed subducted slabs to be identified in the mantle even when they are no longer seismogenic. How well do tomographic models from different researchers compare?

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The shrinking of Adria

Adria, or at least that bit of it positioned near the top of the crustal stack, just got a little bit smaller. At about half past eight local time in the morning of the 9th of November 2022, a Magnitude 5.6 earthquake nucleated at a nominal depth of 10 km beneath the Adriatic sea near Ancona.

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