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火山活动波动吗?

2014 - 05 - 07 - t18:47:09z

根据< a href = " http://iceagenow.info/2012/04/volcanic-activity-increasing/ " rel = " noreferrer " > < / >人的猜测,火山活动看起来是增加。然而, 根据< a href = " http://www.volcano.si.edu/faq.cfm/ " rel = " noreferrer " > < / >报告,火山活动可能不是增加。 我的问题是: 火山活动波动吗? 如果是这样,这个火山活动的波动会导致什么? 图像引用的两个:< img src = " https://i.stack.imgur.com/oIPI7.png " alt = "火山活动随着时间的" > < a href = " http://www.volcano.si.edu/faq.cfm/ " rel = " noreferrer " >图片:史密森尼国家自然历史博物馆的,全球火山机构< / > 这是波动或记录增加吗?

答案由tobias47n9e火山活动波动吗?

2014 - 05 - 07 - t19:09:56z

这可能是一种观察效应在地球科学中十分常见。江南体育网页版在科学发展的社会有一个更高比例的观察由于数量的影响: < ul > <李>科学意识(不解释这是一个奇迹)< /李> <李>记录事件的能力< /李> <李>能力观察(认为12小时一天在工厂和免费周末)< /李> <李>技术远程观察李< / > <李>…江南登录网址app下载< /李> < / ul > 这也是为什么越来越多的陨石观察下降。在中世纪你要么忙着照顾,把它作为一个奇迹,或找到一个陨石,但没有能力把它写下来。类似的火山喷发的场景。我可以想象,实际上所有的船只,飞机,和oudoor-activities(无过错)火山喷发导致更多的观察,但是,人们忙着记录并写下来。地质学家发现war-necessary资源的时间可能是忙。 来源: < ul > <李> < a href = " http://www.volcanodiscovery.com/de/volcanoes/faq/is-volcanic-activity-increasing.html " > http://www.volcanodiscovery.com/de/volcanoes/faq/is-volcanic-activity-increasing.html < / > < /李> < / ul >

答案由kaberett火山活动波动吗?

2014 - 05 - 08 - t15:15:22z

火山活动是否波动,而取决于你正在看的时间尺度。< a href = " http://www.sciencedirect.com/science/article/pii/0377027384900398 " rel = " nofollow noreferrer " >脆(1984)< / >编译可用火成岩活动持续了超过300年的数据,得出结论:在过去的1.8亿年里年均岩浆产量每年约30公里<一口> 3 < /一口>,其中~ 75%是产生在大洋中脊。 最明显的变化在输出岩浆起源于洪流玄武岩喷发,结果经常与大陆裂谷作用有关,建议从第一个新的热上涌地幔柱的影响。这些是巨大的事件——大约10 <一口> < /一口> 6公里<一口> 3 < /一口>岩浆侵位时间尺度短一百万多年,总是不到1000万年,虽然他们占>陆内火山活动的95%,他们只占大约5%的全球岩浆输出由于其罕见。 所以,是的,在短时间尺度上火山活动可以和波动,输出率通常较高而大火成岩省侵位正在进行——实际上很长时间尺度(如果地球是一个在其早期历史中岩浆海洋,它有更多的火山活动比现代表面!)。然而,在媒介时间表-地质学家通常感兴趣的平均输出率相当稳定。 < a href = " //www.hoelymoley.com/a/631/105 " >已经提到了< / > < a href = " http://www.usgs.gov/faq/categories/9830/3355 " rel = " nofollow noreferrer " > < / >关于地震,地震是 的频率增加。要点,与地震、改进技术和人口密度增加。江南登录网址app下载人口密度的增加会更多的被观测到的事件,事件和个人有更大的负面影响;科技的进步,更容易执行远程观察,江南登录网址app下载和识别远程爆发在地质的过去。特别是,与南极冰芯(我们已经记录了800000年在这一点上,和工作正在进行过核心!)允许识别离散喷发的因为他们存款的细灰层,或者更远,acid-rich层。 These eruptions can be correlated with one another between different cores - and even ice cores taken from different continents - through massive "marker" eruptions, such as Krakatoa, and to some extent through absolute dating via isotope chemistry in air bubbles trapped within the ice. However, even as our ability to interpret ice cores further and further back improves, our estimates of global magmatic activity stay pretty constant: despite being published 30 years ago, Joy Crisp's paper is still considered a decent piece of work worth citing.

ETA I note that the first report you cite, at "iceagenow.com", says about the author:

Felix is not affiliated with any university, scientific establishment, or corporation, and therein lies his strength. Untainted by institutional bias or conventional wisdom this architect turned author brings fresh insight to the study of the ice ages.

I suggest that he is probably less reliable than scientific consensus; peer review has its flaws but does exist for a reason! If you would like a close reading and critique of his report, can you make that clear? Cheers :-)

答案由foobarbecue火山活动波动吗?

2015 - 04 - 01 - t11:01:37z

前面的答案包含重要的事实,但忽视最近发现。正如tobias47n9e所说,观察输出随时间的增加是一个观察效果。kaberett解释说,如果你在谈论megayear时间表,大火成岩省将有一个巨大的影响在timeseries。然而,嘴唇和所有大陆爆发(~ 1公里^ 3 /年)相比就是小巫见大巫了洋中脊海底火山喷发(^ 3 ~ 3公里/年)。 火山学家对回答你的问题取得了重大进展(生产速度趋势吗?周期?)在过去的几年里。 我们得知: < ul > <李>融化冰盖火山增加输出,从摘要:< ul > <李>施密特,彼得,et al。”效应的存在量天冰川的消失在冰岛上地幔熔体生产利率。”Journal of Geophysical Research: Solid Earth 118.7 (2013): 3366-3379.

Lowering sea level causes an increase midocean ridge volcanic output, from these papers:

Tolstoy, Maya. "Mid‐ocean ridge eruptions as a climate valve." Geophysical Research Letters (2015).
Crowley, John W., et al. "Glacial cycles drive variations in the production of oceanic crust." Science 347.6227 (2015): 1237-1240.

The authors attributed these effects to decompression melting. If you remove a weight from above a magma chamber, the pressure in the chamber is reduced, and the melting temperature is lowered, causing an increase in the amount of melt available for eruption. (Personally, I suspect that it's not really decompression melting causing the change in eruption rate but actually just fractures opening and closing.)

The Tolstoy paper claims that if you look at seafloor topography, you see bumps where more lava erupted and piled up higher. Further, it says those bumps correlate with the 100,000 year Milankovitch global climate cycle. So, orbital eccentricity --> sea level --> midocean ridge eruption rate --> seafloor topography. This is a brand new idea and needs much more testing. (Personally, I find the topography thing hard to believe because that topography is probably more fault-controlled than eruption-rate-controlled.)

Tolstoy even claims that low tide causes eruptions! She uses a Schuster test to say that the majority of seafloor eruptions occur during neap tide. However, we don't observe seafloor eruptions very often, so she is making this claim using only 9 data points.

It's currently unknown whether these unloading / loading effects are important at subduction zones or LIP.

You've asked a difficult question which volcanologists have been attempting to understand for decades and will continue to work on for the foreseeable future. In summary, my answer is that cutting-edge research suggests that global eruption rate fluctuates in response to climate via changes in the masses pushing down on magma reservoirs.

答案由PCARR火山活动波动吗?

2015 - 04 - 05 - t09:53:16z

我想很快强调月球和其他天体力学的forward-mindedness看着在全球爆发波动率。因为它不只是海洋波纹在应对其他身体的经过,它可能是包容,会有一些通量依照重力潮汐。 在这种情况下,轨道共振 很可能成为一个重要的考虑在地球上火山活动的研究,我们已经知道,火山活动在太阳系的其他地方可以证明这是潮汐运动摩擦。

答案由punkerplunk火山活动波动吗?

2015 - 07 - 06 - t07:04:38z

一个有趣的观察: 当我看着陨石坑的系列标志着各种热点的队伍,如黄石,似乎是它们的大小和输出增加。夏威夷和马达加斯加也一样(如果你忽略了德干地盾。)。尽管这可能只是因为侵蚀,我不清楚。

回答灰的火山活动波动吗?

2018 - 05 - 08 - t11:30:53z

报告偏见,长期和有一个保存的偏见以及小爆发以来< a href = " https://en.wikipedia.org/wiki/Mount_Ruapehu # Volcanic_activity”rel = " nofollow noreferrer " >鲁阿佩胡1995 - 96 < / >将不会出现在化石记录 经过几百年的侵蚀。这些天我们看世界的角度与更大的关注远远超过在任何阶段在过去我们看到火山爆发,我们就不会注意到在过去的。这就是为什么图中有明显的下降在世界大战期间,火山没有停止,但其他地方的人们忙于其他事情。