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New study shows microbes trap massive amounts of carbon 新闻
来源平台:EurekAlert. 发布日期:2021
作者:  admin
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Extreme climate after massive eruption of Alaska's Okmok volcano in 43 BCE and effects on the late Roman Republic and Ptolemaic Kingdom 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (27) : 15443-15449
作者:  McConnell, Joseph R.;  Sigl, Michael;  Plunkett, Gill;  Burke, Andrea;  Kim, Woon Mi;  Raible, Christoph C.;  Wilson, Andrew, I;  Manning, Joseph G.;  Ludlow, Francis;  Chellman, Nathan J.;  Innes, Helen M.;  Yang, Zhen;  Larsen, Jessica F.;  Schaefer, Janet R.;  Kipfstuhl, Sepp;  Mojtabavi, Seyedhamidreza;  Wilhelms, Frank;  Opel, Thomas;  Meyer, Hanno;  Steffensen, Jorgen Peder
收藏  |  浏览/下载:17/0  |  提交时间:2020/06/29
ice core  volcano  Okmok  Rome  climate forcing  
Extreme rainfall triggered the 2018 rift eruption at Kilauea Volcano 期刊论文
NATURE, 2020, 580 (7804) : 491-+
作者:  Cloutier, Richard;  Clement, Alice M.;  Lee, Michael S. Y.;  Noel, Roxanne;  Bechard, Isabelle;  Roy, Vincent;  Long, John A.
收藏  |  浏览/下载:33/0  |  提交时间:2020/05/13

The May 2018 rift intrusion and eruption of Kilauea Volcano, Hawai'  i, represented one of its most extraordinary eruptive sequences in at least 200 years, yet the trigger mechanism remains elusive(1). The event was preceded by several months of anomalously high precipitation. It has been proposed that rainfall can modulate shallow volcanic activity(2,3), but it remains unknown whether it can have impacts at the greater depths associated with magma transport. Here we show that immediately before and during the eruption, infiltration of rainfall into Kilauea Volcano'  s subsurface increased pore pressure at depths of 1 to 3 kilometres by 0.1 to 1 kilopascals, to its highest pressure in almost 50 years. We propose that weakening and mechanical failure of the edifice was driven by changes in pore pressure within the rift zone, prompting opportunistic dyke intrusion and ultimately facilitating the eruption. A precipitation-induced eruption trigger is consistent with the lack of precursory summit inflation, showing that this intrusion-unlike others-was not caused by the forceful intrusion of new magma into the rift zone. Moreover, statistical analysis of historic eruption occurrence suggests that rainfall patterns contribute substantially to the timing and frequency of Kilauea'  s eruptions and intrusions. Thus, volcanic activity can be modulated by extreme rainfall triggering edifice rock failure-a factor that should be considered when assessing volcanic hazards. Notably, the increasingly extreme weather patterns associated with ongoing anthropogenic climate change could increase the potential for rainfall-triggered volcanic phenomena worldwide.


Immediately before and during the eruption of Ki & x304  lauea Volcano in May 2018, anomalously high rainfall increased the pore pressure in the subsurface to its highest level in 50 years, causing weakening and mechanical failure of the edifice.


  
Coupling of Indo-Pacific climate variability over the last millennium 期刊论文
NATURE, 2020
作者:  Chow, Brian W.;  Nunez, Vicente;  Kaplan, Luke;  Granger, Adam J.;  Bistrong, Karina;  Zucker, Hannah L.;  Kumar, Payal;  Sabatini, Bernardo L.;  Gu, Chenghua
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Coral records indicate that the variability of the Indian Ocean Dipole over the last millennium is strongly coupled to variability in the El Nino/Southern Oscillation and that recent extremes are unusual but not unprecedented.


The Indian Ocean Dipole (IOD) affects climate and rainfall across the world, and most severely in nations surrounding the Indian Ocean(1-4). The frequency and intensity of positive IOD events increased during the twentieth century(5) and may continue to intensify in a warming world(6). However, confidence in predictions of future IOD change is limited by known biases in IOD models(7) and the lack of information on natural IOD variability before anthropogenic climate change. Here we use precisely dated and highly resolved coral records from the eastern equatorial Indian Ocean, where the signature of IOD variability is strong and unambiguous, to produce a semi-continuous reconstruction of IOD variability that covers five centuries of the last millennium. Our reconstruction demonstrates that extreme positive IOD events were rare before 1960. However, the most extreme event on record (1997) is not unprecedented, because at least one event that was approximately 27 to 42 per cent larger occurred naturally during the seventeenth century. We further show that a persistent, tight coupling existed between the variability of the IOD and the El Nino/Southern Oscillation during the last millennium. Indo-Pacific coupling was characterized by weak interannual variability before approximately 1590, which probably altered teleconnection patterns, and by anomalously strong variability during the seventeenth century, which was associated with societal upheaval in tropical Asia. A tendency towards clustering of positive IOD events is evident in our reconstruction, which-together with the identification of extreme IOD variability and persistent tropical Indo-Pacific climate coupling-may have implications for improving seasonal and decadal predictions and managing the climate risks of future IOD variability.