The field of dendrochronology studies tree rings. The latter can convey accurate information about the age of trees, climate trends, and past events going
Ancient Tree Shows Result of Magnetic Pole Switch goodmenproject.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from goodmenproject.com Daily Mail and Mail on Sunday newspapers.
Do terrestrial geomagnetic field reversals have an effect on Earth s climate? Cooper et al.created a precisely dated radiocarbon record around the time of the Laschamps geomagnetic reversal about 41,000 years ago from the rings of New Zealand swamp kauri trees. This record reveals a substantial increase in the carbon-14 content of the atmosphere culminating during the period of weakening magnetic field strength preceding the polarity switch. The authors modeled the consequences of this event and concluded that the geomagnetic field minimum caused substantial changes in atmospheric ozone concentration that drove synchronous global climate and environmental shifts.
Geological archives record multiple reversals of Earth’s magnetic poles, but the global impacts of these events, if any, remain unclear. Uncertain radiocarbon calibration has limited investigation of the potential effects of the last major magnetic inversion, known as the Laschamps Excursion
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Fish Factor:Alaskans Prepare for Poor to Average Salmon Runs By LAINE WELCH - Alaskans are preparing for another salmon season of poor to average runs to most regions.
The big exception once again is at Bristol Bay where another massive return of more than 51 million sockeyes is expected. Managers predict that surge will produce a harvest of over 36 million reds to fishermen.
Bristol Bay is home to the largest wild sockeye salmon run in the world and typically accounts for 42% of the world’s sockeye harvest. Those fish and all wild salmon compete in a tough worldwide commodities market, where Alaska salmon claims 13% of the global supply.
Ancient Northland swamp kauri solves 42,000 year old mystery
21 Feb, 2021 05:00 PM
7 minutes to read
Some of this giant ancient swamp kauri tree uncovered at Ngāwhā has been used by researchers to confirm the date when the Earth reversed its magnetic poles. Photo / Peter de Graaf
Northern Advocate
Ancient swamp kauri from Northland has been used to confirm a temporary breakdown of Earth s magnetic field 42,000 years ago sparked major climate shifts leading to global environmental change and mass extinctions.
A new international study using ancient swamp kauri from Ngāwhā shows this dramatic turning point in Earth s history was triggered by a reversal of Earth s magnetic poles and changing solar winds.