Extreme and persistent drought in California and Patagonia during medieval time

Nature Portfolio (Springer Nature) | June 16th, 1994

STUDIES from sites around the world1–5 have provided evidence for anomalous climate conditions persisting for several hundred years before about AD 1300. Early workers

STUDIES from sites around the world1–5 have provided evidence for anomalous climate conditions persisting for several hundred years before about AD 1300. Early workers emphasized the temperature increase that marked this period in the British Isles, coining the terms 'Mediaeval Warm Epoch' and 'Little Climatic Optimum', but many sites seem to have experienced equally important hydrological changes. Here I present a study of relict tree stumps rooted in present-day lakes, marshes and streams, which suggests that California's Sierra Nevada experienced extremely severe drought conditions for more than two centuries before ad ∼ 1112 and for more than 140 years before ad ∼ 1350. During these periods, runoff from the Sierra was significantly lower than during any of the persistent droughts that have occurred in the region over the past 140 years. I also present similar evidence from Patagonia of drought conditions coinciding with at least the first of these dry periods in California. I suggest that the droughts may have been caused by reorientation of the mid-latitude storm tracks, owing to a general contraction of the circumpolar vortices and/or a change in the position of the vortex waves. If this reorientation was caused by mediaeval warming, future natural or anthropogenically induced warming may cause a recurrence of the extreme drought conditions.

Fish and Game Commission Twenty-Second Biennial Report for the Years 1910-1912

State of California | December 31st, 1912

From Desert Wasteland to Agricultural Wonderland: The Story of Water and Power

Imperial Irrigation District (IID) | October 3rd, 1977

From past patterns to future potential: using historical ecology to inform river restoration on an intermittent California river

Landscape Ecology (Springer) | August 30th, 2015

Although human actions have greatly impacted the river’s extent, baseflow hydrology, and riparian habitats, many ecological attributes persist in more limited form, in

Although human actions have greatly impacted the river’s extent, baseflow hydrology, and riparian habitats, many ecological attributes persist in more limited form, in large part facilitated by these fundamental hydrogeological controls. By drawing on a heretofore untapped dataset of spatially explicit and long-term environmental data, these findings improve our understanding of the river’s historical and current conditions and allow the derivation of reach-differentiated restoration and management opportunities that take advantage of local potential.

From the Sierra to the Sea: The Ecological History of the San Francisco Bay-Delta Watershed

Bay Institute | July 15th, 2003

A vast watershed connects the mountain streams surrounding California’s Central Valley with San Francisco Bay and the ocean beyond. Over the course of the last two cent

A vast watershed connects the mountain streams surrounding California’s Central Valley with San Francisco Bay and the ocean beyond. Over the course of the last two centuries, much of the natural productivity, biodiversity and ecological integrity of the watershed has been destroyed by modifying the environment without fully understanding the long-term environmental consequences. Long the site of some of the nation’s most intensive conflicts over the use of land and water resources, this system is now emerging as the focus of one of the most ambitious ecological restoration efforts ever undertaken in the United States. This report was designed to provide a coherent and defensible ecological framework and information base for restoration. The need for such an historical, broad-scale perspective on system ecology stems from two fundamental principles of ecological restoration - the need to manage toward a natural template and to manage at ecosystem and landscape levels.

From the Sierra to the Sea: The Ecological History of the San Francisco Bay-Delta Watershed

Bay Institute | January 1st, 1998

A vast watershed connects the mountain streams surrounding California’s Central Valley with San Francisco Bay and the ocean beyond. Over the course of the last two cent

A vast watershed connects the mountain streams surrounding California’s Central Valley with San Francisco Bay and the ocean beyond. Over the course of the last two centuries, much of the natural productivity, biodiversity and ecological integrity of the watershed has been destroyed by modifying the environment without fully understanding the long-term environmental consequences. Long the site of some of the nation’s most intensive conflicts over the use of land and water resources, this system is now emerging as the focus of one of the most ambitious ecological restoration efforts ever undertaken in the United States. This report was designed to provide a coherent and defensible ecological framework and information base for restoration. The need for such an historical, broad-scale perspective on system ecology stems from two fundamental principles of ecological restoration - the need to manage toward a natural template and to manage at ecosystem and landscape levels.

Gold Extraction Processes

Scientific American | October 31st, 1896

FROM very early times the ancients were attracted the beautiful color, the brilliant luster and the indestructibility of gold, and spared no pains in the endeavor to acqu

FROM very early times the ancients were attracted the beautiful color, the brilliant luster and the indestructibility of gold, and spared no pains in the endeavor to acquire it. In the code of Menes, who reigned in Egypt some 2,000 years before the time of Moses, the ratio of value between gold and silver is mentioned, one part of gold being declared equal in value to two and a half parts of silver, and it is, therefore, clear that the extraction of both metals from the deposits containing them must have been carried on before that time. It is indeed probable that gold was the first metal observed and collected, since it occurs in fragments of all sizes in loose sand, and the operations of collecting the larger pieces and melting them together are so simple. Among the rock carvings of Upper Egypt there are several illustrative of the art of washing auriferous sands by stirring and working them up by the hand in hollowed-out stone basins, and subsequently melting the gold in simple furnaces with the aid of mouth blowpipes. The earliest of these carvings is supposed to date back to about 2,500 B.C. However, in ancient times, gold appears to have been mainly derived from India, and that country continued to supply most of the gold used in Europe until the discovery of America by Columbus.

Gone. Decades of greed, neglect, corruption, and bad politics led to last year’s Paradise fire, the worst in California history. It should never have happened. It will happen again.

California Sunday Magazine | July 31st, 2019

By the time I made it to Paradise, the deadliest wildfire in California history was four months past, and the burned-out ridge between the two river canyons was pouring

By the time I made it to Paradise, the deadliest wildfire in California history was four months past, and the burned-out ridge between the two river canyons was pouring rain. I was riding the Skyway, the road from Chico to Paradise, flatland to hilltop, trying to understand what forces had conspired last November to create a blaze of such anger that it took the lives of 85 people and destroyed 19,000 structures. I had puzzled out enough disasters to know that tragedy was a force of intricate construction. It wasn’t one detached act that materialized as tragedy but myriad smaller acts — some incidental, some accidental, others malevolent — that lined up in perfect continuity. Had one circumstance in the sequence lost its footing, a cosmic stumble, the next circumstance would have never hitched on, and tragedy would have been averted.

Governor's Commission to Review California Water Rights Law: Final Report

California State Water Resources Control Board (SWRCB) | December 22nd, 1978

The Final Report of the Governor's Commission to Review Water Rights Law, dated 12/22/1978.  The report contains the Commission's analysis of existing California water r

The Final Report of the Governor's Commission to Review Water Rights Law, dated 12/22/1978.  The report contains the Commission's analysis of existing California water rights law and recommendations for modifications. The Commission recommended 'modernization' in four areas:  water rights, efficiency in water use, instream uses of water, and groundwater.

Helium isotope studies in the Mojave Desert, California: implications for groundwater chronology and regional seismicity

Chemical Geology (Elsevier) | November 7th, 2003