Geology news

Hot Spots

At https://phys.org/print422274566.html ... Rice University geophysicists have developed a method that uses the average motion of hot spots to determine how fast plates are moving. Hot spots are thought to lie along plate boundaries - but not universally as some hot spots occur inside plates (rather than at margins). What does this mean?

lithosphere research

At https://phys.org/print421653227.html ... researchers at the University of Southampton have been looking at the thickness of Earth's continents (results published in the journal Science) by using seismic reflections to gain a better understanding of craton boundaries. The Earth's lithosphere includes the oceans, crust, and portions below this, which sit upon the Mantle. The lithosphere includes the continents - but how thick are they? They mkae use of seismic waves generated naturaly by hundreds of earthquakes.

Magnetic stripes

Peter M James has a new article at www.ncgt.org June issue. He has been a long time critic of Plate Tectonics and notes that over the last 50 years there has been a lot of criticism of the hypothesis by geologists, admittedly a minority, but this has had little impact. He adds that critical importance is no doubt related to the fact that the mechanisms involved in the mobilist mainstream model are still of unknown magnitude and/or are taken to act at unknown depths, beyond the gaze of the critics (and the proponents).

Zealandia Research

At https://phys.org/print420432849.html ... scientists are hoping to get a better handle on Zealandia during an exploration that began this week in Australia. As a geologist has said, Zealandia has everything any other land mass has - except it is under the waves. We may assume it was above sea level at one time, particularly pertinent if the geoid had changed in the past. Zealandia extends from south of New Zealand to New Caledonia in the north, and from the Kam Plateau off the coast of Australia to some distance into the Pacific.

dunes under the sea

Gary sent in the following links - www.dailymail.co.uk/sciencetech/article-4707418/Are-tales-legendary-King... .... which concerns a book by a controversial historian who seems to have hit on a way to make money by re-writing history, and www.dailymail.co.uk/sciencetech/article-4697502/NASA-image-reveals-patte... ...--- NASA images show patterns exposed in giant crater. There are a lot of images to look at and digest but what kind of impact was involved - a meteor or an electrical discharge.

Sahara Dust

At https://phys.org/print419683970.html ... geo-scientists have realised dust from the Sahara can play a role in defining Holocene history - and well watered periods of life in the Sahara. A sediment core from Lake Sidi in the Moroccan Atlas Mountains has revealed phases of Sahara dust capture that coincides with arid periods after 12,000 years ago. These are thought to have an origin in dust storms in what is now the Sahara desert and they have been dated at 10,200, 8,200 and between 6600 and 6000 years ago.

Mud Volcanoes

At https://tallbloke.wordpress.com/2017/07/19/ten-year-old-mud-volcano-baff... ... (see also http://en.wikipedia.org/wiki/Sidoarjo_mud_flow ) which tells you all you need to know about the biggest known mud volcano in the world, close by Sidoarjo in Java. It erupted eleven years ago and has not stopped since then. At its peak it disgorged 180,000 cubic metres of mud every day, buring villages under mud up to 40m thick.

Sixth Extinction

At www.media.uzh.ch/en/Press-Releases/2017/marine-Megafauna.html ... University of Zurich researchers have homed in on an extinction event around 2 million years ago when a third of large marine animals, or megafauna as they describe them, such as sharks, whales, sea birds and sea turtles appear to have gone missing. Why did they disappear? It could have had an impact on the ocean ecosystem they conclude, drawing a parallel with the role of humans in the modern world. However, the event 2 million years ago was clearly catastrophic, as they go on to show (using models as well as data).

Expansion

Laurence Dixon sent in details of a Royal Society paper by GG Nyambuya of the Dept of Physcis at Bulawayo University. He begins by saying 100+ years ago Alfred Wegener claimed Eareth's continental plates receded from each other over the course of Earth's history - the theory of continental drift. He also said they were stilll in a state of motion relative to one another. In order to explain this Wegener came up with the possibility the earth must be expanding. In reality, he had no adequate explanation as to why the plates were moving apart or the energy source responsible.

Sahara Sand

Gary Gilligan sent in this link to www.godkingscenario.com/blog/sand-sahara-come   ... which concerns his book, 'Extraterrestrial Sands'. The link provides a series of images of sand in the deserts of the world. He points out that from a landscape of lakes and savannah grassland, in the first half of the Holocene period, the Sahara degenerated into a dry and very arid swathe or band that stretched right across North Africa into the Arabian peninsular and even as far as the Thar Desert in India. Where did all that sand come from?