Category Archives: Gravity Anomalies

Late Cretaceous Orogenic North American Continental Margin

A huge problem with geological maps is that their daunting psychedelic maze of colors makes it very difficult to bear down on specific features. We recently discovered a GIS series of State scale maps from USGS  where it is possible to … Continue reading

Posted in Geography, Geology, Gravity Anomalies, Paleogeography, Plate Tectonics | Tagged , , | 1 Comment

Gravity Signals of Extensional Sialic Crustal Regimes

I have always loved the poorly named Great Basin of the Western United States. Yes, its maze of lowlands held a lot of glacial meltwater during the last glacial maximum before letting it percolate out to the Columbia and the Sea … Continue reading

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The Hawaiian/Emperor Seamounts and How Island Arcs are Formed

Ever wonder why offshore island arcs should form at random spots in the oceans? No? Don’t worry, its a far fig newton. We offer here the suggestion that the locations are not random, that island arc trenches and probably spreading ridges and … Continue reading

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Posted in Geography, Geology, Gravity Anomalies, Seamount Chains as Incipient Island Arcs | Tagged , , , | 1 Comment

Granite Rafts

Continents are granite rafts. We believe that granite is formed when thoroughly hydrated ocean floor sinks at a subduction zone or trench, often at the edge of a continent. When it sinks deep enough it gets cooked at very high … Continue reading

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Hawaii

By incredibly good luck I’ve been spending lots of time in Hawaii lately, on business no less. I stay in this unbelievable house.   One really gets the sense of being out in the middle of the ocean in Hawaii, … Continue reading

Posted in Geography, Geoid, Geology, Gravity Anomalies, Oceanography, Plate Tectonics | Tagged , , , | 1 Comment

California Great Central Valley as a Cretaceous Sea of Cortez

I was travelling the world as I often do in Google Earth, pondering how strange it is that the Hawaiian Seamount chain created a gravity low its entire length, when I noticed this: Probably just because gravity lows are a nice deep … Continue reading

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Bad Hair Days and Magnetic Excursions

This picture of a model simulating the weakened and divided magnetic field during a reversal should be in the thesaurus when you look up “bad hair day”. If this is anywhere near correct it should be no surprise that the nano … Continue reading

Posted in Gravity Anomalies, Magnetic Reversals, True Polar Wander, Virtual Geomagnetic Pole (VGP) | Tagged , , , | Leave a comment

Gravity and Magnetism

This post follows the last two which were inspired by discovering that the virtual geomagnetic pole (VGP) wander path during the Laschamp reversal as revealed in Black Sea sediments by the work of Norbert R. Nowaczyk consistently follows lows in … Continue reading

Posted in Geography, Geoid, Geology, Gravity Anomalies, Gravity Potato, Magnetic Reversals, True Polar Wander, Virtual Geomagnetic Pole (VGP) | Tagged , , , , | Leave a comment

Further Musing on the Affinity of Magnetic North for Gravity Holes During the Laschamp Reversal.

We know so little about what this means that it may be helpful to focus on what the gravity geoid is not. The earth is NOT shaped like a potato. Vertical exaggeration is used on nearly all maps to keep them … Continue reading

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Simplified Path of Magnetic North During 41kya Reversal on Current Geoid

There was this really cool Hemholtz plot of the path of magnetic north during the last geomagnetic reversal from wander paths of sediments in the Black Sea. Had a sense that it was avoiding the geoid gravity high knob in Indonesia and decided … Continue reading

Posted in Geography, Geoid, Geology, Gravity Anomalies, Gravity Potato, Magnetic Reversals, True Polar Wander | Tagged , , , , , , , | Leave a comment