Taxonomy term

geology

Geologic Column: A world without measure

The treaty establishing a global, uniform system of measurement was signed on May 20, 1875. Today, we honor that achievement by celebrating World Metrology Day on May 20.

20 May 2018

Data-driven discovery reveals Earth's missing minerals

New discoveries in mineralogy, one of the oldest human endeavors, are arising from a new sort of mining—data mining. Mineralogists are applying statistical models and data science techniques to reveal previously unseen patterns and clues hidden in mineralogical databases, and to find undiscovered minerals.
18 May 2018

Swelling clay slows landslides

Rainfall can trigger landslides, and it can also cause slow-moving slides to speed up. But researchers have observed that rain also appears to cause landslides composed of clay-rich material to take longer to start moving, and to move slower than expected.

17 May 2018

When more humidity means less water

Scientists have long assumed that temperature is the main control on melting of winter snowpacks across the mountainous western United States. In a recent study, however, scientists suggest that regional humidity may have a larger impact than temperature.

16 May 2018

Rising waters sink seafloors

Predicting how much the ocean surface will rise in the coming years requires complicated, global-scale bookkeeping of the many factors that affect sea levels. In a new study, scientists have, for the first time, quantified the role of ocean-bottom deformation — the gradual deepening of ocean basins under the weight of more water — in both global and regional sea-level rise, an effort that may help produce more accurate sea-level projections.

13 May 2018

El Nino "flavors" affect California rainfall

Twenty years ago, the 1997–98 El Niño surpassed the 1982–83 event to become the strongest El Niño ever recorded, contributing to famine and drought in Southeast Asia, devastating floods in Southern California, and other natural disasters. By many metrics, the 2015–16 El Niño bested both to claim the title of the strongest El Niño on record. This most recent event, nicknamed the “Godzilla El Niño,” did contribute to extreme weather in parts of the world, including disastrous fires in Indonesia and the longest, global coral-bleaching event on record. However, it did not have the anticipated effect on California, which, at the time, was in the midst of a severe multi-year drought. In a recent study, researchers suggest the 2015–16 El Niño was the wrong “flavor” to bring heavy precipitation to the state.

13 May 2018

Geologic evidence confirms existence of 405,000-year Milankovitch cycle

Earth’s rock record preserves evidence of numerous natural processes, from evolution and extinction to catastrophes and climate change, and sometimes even planetary configurations. In a new study, a well-preserved sequence of Triassic lake sediments bearing evidence of cyclical patterns of climate change in the Newark Basin confirms the existence of a Milankovitch cycle — a periodic change in the shape of Earth’s orbit caused by, in this case, Earth’s gravitational interactions with Jupiter and Venus. The finding can be used to precisely date other events in the geological record, and inform climate and astronomical models.

11 May 2018

Oceanic crust in all its glory

Our loop drive through the high Hajar Mountains boasted excellent exposures of every oceanic crustal layer. One good exposure of the sequence of mantle rocks is found in the hills surrounding Oman’s capital city Muscat. They consist of a variety of peridotite called harzburgite, which is the pyroxene-depleted residue left behind after basaltic magma is extracted. That extracted magma forms the oceanic crust, whose characteristic rock sequence is, from bottom to top: 1) dark, layered gabbro overlain by massive gabbro (the intrusive equivalent of basalt that comprises solidified magma chambers); 2) sheeted basaltic dikes (the conduits that transported lava from the magma chambers up to the ocean floor); and 3) bulbous pillow lavas, which form when basalt erupts directly into seawater.

06 May 2018

Getting there and getting around Oman

Oman’s main gateway is Muscat International Airport (MCT), which offers service to most major Middle Eastern and European cities. There are no direct flights to Oman from North America; it’s usually most convenient to fly through Dubai, Doha, Bahrain or a major European city. Emirates, Qatar Airways, Gulf Air, Oman Air and Turkish Airlines are among those that offer connecting service.

06 May 2018

Travels in Geology: Northern Oman: Stunning canyons, towering dunes and the world's largest ophiolite

The small, politically stable sultanate of Oman hosts the world’s biggest and most intact ophiolite — a rare slice of oceanic crust emplaced on land — as well as stunning canyons, turquoise swimming holes, lush palm oases, Bronze Age tombs, endangered sea turtles and endless fields of sand dunes.
 
06 May 2018

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