YELLOWSTONE NATIONAL PARK, Wyo. - Semakin banyak gegaran di Yellowstone National Park.
Gegaran-gegaran kecil termasuk tiga gegaran pada Jumaat lalu yang berukuran 3.0 magnitud. Pihak University of Utah Seismic Station berkata bahawa gegaran yang terkuat setakat ini adalah 3.5.
Beberapa ratus gegaran berpusat di bawah bahagian hujung utara Tasik Yellowstone telah berlaku sejak 26 Disember. Tiada kerosakan dilaporkan. Himpunan gempa bumi biasa berlaku di Yellowstone. Tetapi para saintis berkata ianya adalah luar biasa untuk berlaku gegaran yang banyak dalam temph beberapa hari. Sebahagian besar Yellowstone terletak di barat laut Wyoming di mana ianya adalah sebahagian daripada sebuah gunung berapi yang meletus 70,000 tahun dahulu. Saintis masih belum dapat merumuskan apakah yang menyebabkan gegaran-gegaran tersebut.
Jika Yellowstone ni meletus semula, ianya boleh menyebabkan mass extinction, kerana ianya tidak meletus selama 70,000 tahun. Yellowstone ni dikategorikan sebagai super volcano. Jika ia meletus ianya akan mengakibatkan perubahan climate yang sangat ketara. Letusan paling dahsyat berlaku pada 2.1 juta tahun dahulu di mana ianya melepaskan 2,450 kilometer persegi volcanic materials.
ader ceirta kan kat discovery channel pasal gunung berapi yellowstone kan? dalam cerita tu plat tektonik berlanggar sesama sendiri... abis dah bumi....
tapi yang ni impaknya terhadap climate bumi. bila super volcano meletus, abu gunung berapi akan menyelubungi seluruh bumi, matahari takkan dapat tembus ke bumi, lantas kebanyakan tumbuhan akan mati, dan menyebabkan kekurangan makanan yang dahsyat, dan tak habis dengan tu, pada penghujung krisis ni, hujan asid akan turun ke bumi dan akan menyebabkan air tercemar. so takde makanan, takde air = mass extinction.
tapi kalau at least 400 gempa yg tercatat since 26th december ..
dalam masa seminggu tu ada 400 gempa kecik .. rasa2 cam normal ke?
sblom ni biasa aa kan gempa2 kecik .. tapi aku rasa takde aa terlalu kerap & terlalu banyak ..
ni dah catat 400 dalam masa seminggu .. aku rasa macam terlalu banyak jek ..
2009 State of Emergency for Yellowstone National Park has had over 500 earthquakes in the last five days of 2008. Chris Sanders the President of The Gas Company who is also a geologist has been tracking the possible eruption of this super volcano for the last few months. Now January 1, 2009 Chris is advising that all people visiting and volunteering at Yellowstone National Park leave immediately. "I would rather be wrong than right on this one since it once ended life and should annihilate a radius over 300 square miles minimum when it goes off. Plus all of our technology in place is showing magma moving towards the surface causing movement and earthquakes everywhere
Fears over earthquake 'swarm' at Yellowstone National Park
From Times Online; January 4, 2009
Hundreds of earthquakes have hit Yellowstone National Park, raising fears of a more powerful volcanic eruption.
The earthquake swarm, the biggest in more than 20 years, is being closely monitored by scientists and emergency authorities.
The series of small quakes included three last Friday which measured stronger than magnitude 3.0. The strongest since this latest swarm of quakes began on December 27 was 3.9.
No damage has yet been reported but scientists say this level of activity - there have been more than 500 tremors in the last week - is highly unusual.
"The earthquake sequence is the most intense in this area for some years," said the Yellowstone Volcano Observatory. Some of the larger earthquakes have been felt by park employees and guests, according to the observatory.
The swarm is occurring beneath the northern part of Yellowstone Lake in the park. Yellowstone sits on the caldera of an ancient supervolcano and continuing geothermal activity can be seen in the picturesque geysers and steam holes, such as Old Faithful.
About 1,000 to 2,000 tremors a year have been recorded since 2004. The most devastating earthquake in recent history in the Yellowstone region occurred on August 17, 1959, when a magnitude 7.1 earthquake hit.
It was centered near Hebgen Lake, Montana and it caused landslides that killed 28 people and caused more than $11 million in damage.
Geysers in Yellowstone National park changed eruption times, and new ones began to erupt. On June 30, 1975, a magnitude 6.4 tremor hit the park.
Professor Robert B. Smith, a geophysicist at the University of Utah and one of the leading experts on earthquake and volcanic activity at Yellowstone, said that the swarm was significant.
"It's not business as usual," he said. "This is a large earthquake swarm, and we've recorded several hundred. We are paying careful attention. This is an important sequence."
The last full-scale explosion of the Yellowstone Supervolcano, the Lava Creek eruption which happened approximately 640,000 years ago, ejected about 240 cubic miles of rock and dust into the sky.
Geologists have been closely monitoring the rise and fall of the Yellowstone Plateau as an indication of changes in magma chamber pressure.
The Yellowstone caldera floor has risen recently - almost 3in per year for the past three years - a rate more than three times greater than ever observed since such measurements began in 1923.
From mid-summer 2004 through to mid-summer 2008, the land surface within the caldera moved upwards as much as 8in at the White Lake GPS station. The last major earthquake swarm was in 1985 and lasted three months.
The observatory said similar swarms have occurred in the past without triggering steam explosions or volcanic activity. However, the observatory said there is some potential for explosions and that earthquakes may continue and increase in intensity.
Joe Moore, director of the Wyoming Office of Homeland Security, said his office is tracking the events at Yellowstone on a minute-by-minute basis. "It's being followed very closely," Mr Moore said.
ada satu artikel yg aku baca jap tadik (tapi dah hilang sbb pc aku hang, terus kena restart) ..
yg aku ingat, ranger2 kat situ just komplen susah nak tido malam sbb asyik gegar2
tapi sorang geologist yg stay kat situ kata - memang membimbangkan, tapi MUNGKIN tak bahaya
deme tgh siasat & kaji lagik naper dan aper yg cetuskan tremor2 tuh ..
berdasarkan comments kat satu article yg aku baca tadik, ada yg kata tak payah risau sangat
eventho kalau btol aa erupt; apa yg saintis/geologist ramalkan tu merupakan worst case scenario aa
& MUNGKIN takkan jadik sampai camtu skali (macam kes ramalan mega tsunami tu)
apaperpun, kita tengok & tunggu jek aa perkembangan atau penguncupannya
erm, rasanya bukan kot. sebab debu2 tu suma perlu ada kat permukaan atmofera selama beribu-ribu tahun, baru bumi diseliputi ais.
It is challenging to see how volcanism could cause an ice age, since its cooling effects would have to be stronger than and to outlast its warming effects. This would require dust and aerosol clouds which would stay in the upper atmosphere blocking the sun for thousands of years, which seems very unlikely. Undersea volcanoes could not produce this effect because the dust and aerosols would be absorbed by the sea before they reached the atmosphere.
tu kena monitor gak la. takut kadang2 false alarm.
cluesan .. ikut apa yg aku baca tadik, deme kata dah stop dah siri2 tremor tuh
(tapi dari respon, macam ramai yg tak percaya ngan berita yg dikluarkan tuh)
aku listkan sket points yg aku baca tadik :
+ apa yg jadik skang ni lebih kepada 'major seismic event', banding ngan 'major volcanic event'
+ status yellowstone skang ni kekal pada tahap green alert level
+ rekod gegaran yg terkuat adalah 3.9 , pada kedalaman (max) 10km
kalau ko berminat nak tengok graf report tremors/earthquake kat yellowstone tu, ko bleh klik KAT SINI
ohh.... seismic activity rupanya. bukan volcanic activity. tahun 2003 diorang ada jumpa mcm "bulge" ataupun apa dlm bm ehh... mcm bengkak kat bawah tasik yellowstone. kira permukaan tanah kat bawah tasik tu da rise sebesar 3 padang bolasepak. and ada volcanic activity kat bawah tu.
lagipun volcano yellowstone ni dia ada lifecycle. according diorang, lifecyle yellowstone ni da melebihi apa yg sepatutnya. sepatutnya da lama da meletus.
Event supervolcano terburuk, letusan Gunung Toba 74,000 tahun dulu menghasilkan 2800 km padu bahan dimana 800km padu daripadanya adalah debu manakala 10 bilion tan metrik gas sulfur dioksida dilepaskan ke udara. Dikatakan Malaysia terbenam dibawah 9km debu. Dikatakan letusan tersebut menyebabkan Bumi mengalami volcanic winter selama 6 tahun.
Ok, volanic winter bukan le bermakna bumi diselaputi ais tapi keadaannya cukup buruk - suhu jatuh diseluruh dunia, musim sejuk tiba awal, musim panas yang tak panas..yang menggangu kitaran tanaman dan seterusnya meningkatkan kadar kebuluran.
hmm... it's true. tak sampai jadik Ice Age. tapi keadaan climate pada masa tu dah cukup untuk merosakkan tanaman dan menyebabkan kekurangan makanan yang serius.
Post time 3-1-2009 11:09 AM
变色卡
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