Cross-posted at Highly Allochthonous In case other events have crowded it out of your news feed, there’s record-breaking flooding going on in the Mississippi River basin. Snowmelt in the headwaters, combined with weeks of heavy rains in the middle reaches of the river basin, have pushed the system to its …
Cross posted at Highly Allochthonous Fargo, North Dakota is coming out of its 3rd snowiest winter since 1885. Snow continued to fall into late March, and daytime temperatures have only been above freezing for few weeks. At night, it’s still below freezing, though starting tomorrow night the forecast calls for …
14,000 years ago there was direct connection between what is now the Red River basin and the Minnesota River basin. Today, there’s a continental divide – with the Red flowing toward Hudson Bay and the Minnesota flowing toward the Mississippi and Gulf of Mexico. But what a strange continental divide it is – for it runs through the former outlet of Lake Agassiz, in what is now known as the Traverse Gap. This divide is not so much a high point in the landscape, but a just-not-quite-as-low area.
The geology, geography, and climate of the Red River Valley make major floods an inevitability.
A Geophysical Research Letters paper concludes the 2010 Pakistan floods were predictable, but not predicted. Other reporting suggests they were predicted, but the warning was ignored. Either way, things should have been done differently.
Flooding updates from New Zealand, Australia, South Africa, Saudi Arabia, and Brazil.
For the past two weeks, unusually heavy monsoon rains have deluged Pakistan, resulting in flooding and landslides. Pakistan is heavily populated all along the Indus River valley, so this is a slow-moving disaster of epic proportions. The latest news reports estimate that flooding has displaced 14 million people – more …
These four papers all attempt to understand what controls the sediments that make up the streambed and floodplain and that get preserved in the geologic record. White et al. look at how riffle positions are governed by valley width variations, while Jerolmack and Brzinski find striking similarities in grain size transitions observed in rivers and dune fields. Hart et al. examine the relationship between glacial advances and downstream sediment deposition, while Sambrook Smith et al. investigate the sedimentological record of floods.
How do rivers erode bedrock streams, during big floods, and in the presence of groundwater? Laboratory and accidental experiments are providing some cool new insights.
Cross-posted at Highly Allochthonous The geo-image bonanza of this month’s Accretionary Wedge gives me a good reason to make good on a promise I made a few months ago. I promised to write about what can happen on the flanks of Pacific Northwest volcanoes when a warm, heavy rainfall hits …