Japanese Earthquake

[Cat 5]

Not sure the best place to post this so have gone for the learners area as this is an area I am not too familiar with.

I read somewhere that last year we had a number of earthquakes around the globe with a magnitude of seven or more. A quake of similar strength has been predicted to hit Japan for many years.

Does anyone know when this quake was expected to hit?

Thanks

[J07]

Don't have the answer but I'm curious as to how they define "hit". There were a few decent sized quakes last year off the coast of NZ, magnitudes over 7.0 I think. They were "felt", but did not "hit"- then there was a 6.8 that "hit" in December, though it was centred offshore...is that a "hit" or one that was merely "felt"?

How can a prediction differentiate between whether the quake will hit a populated region, a dense city, open ground or ocean? It must surely be just a statistical fluke if they get it right?

If a 7.0 occurs 50km away from the Japanese shore, does that count as a success for the prediction?

[Cat 5]

Good point. Not sure either. Perhaps they mean mainland Japan as the epicentre.

[robl1200]

Scientists generally believe Earthquakes come in swarms, rather than just random places as previously thought and teached in schools.

A Earthquake will occur and this puts more stress on the plate further along it, this in turn ruptures and so the cycle begins until the plate has released the stress.

Scientists can predict almost where a quake might happen (in a region) but not the exact epicenter or strength..infact Istanbul is believed to have a mjaor Earthquake sometime soon as a result of the Turkish Earthquakes which happened in the mid 1990's, the swarms are transferring Westwards towards the City and is thought will occur somewhere offshore Istanbul.

[summer blizzard]

Scientists generally believe Earthquakes come in swarms, rather than just random places as previously thought and teached in schools.

A Earthquake will occur and this puts more stress on the plate further along it, this in turn ruptures and so the cycle begins until the plate has released the stress.

Scientists can predict almost where a quake might happen (in a region) but not the exact epicenter or strength..infact Istanbul is believed to have a mjaor Earthquake sometime soon as a result of the Turkish Earthquakes which happened in the mid 1990's, the swarms are transferring Westwards towards the City and is thought will occur somewhere offshore Istanbul.

Could a moderator transfer the thread to the science section where it should recieve a greater reply??

http://www.guardian.co.uk/world/2006/dec/0...aturaldisasters

A Very worrying article about that, i'll highlight a few key points...

The southern slab of the North Anatolian fault pushes up from the Arabian peninsula, shifting the northern plate 2.5cm (one inch) towards Greece, a very fast rate of rupture.

In 2004, Tom Parsons of the survey team reported that the probability had risen to as high as 70% that an earthquake of at least 7.6 on the Rictor Scale would strike Istanbul by 2030.

A 7.6 quake in the Sea of Marmara could hit 40% of the city, affecting up to 5 million people. A "mini-tsunami" up to seven metres high is also feared from the Sea of Marmara. Others talk of "only" 10,000 buildings being destroyed.

Mr Eke, the psychologist, said the most optimistic scenario was that a big earthquake would leave a minimum of 10% of the inhabitants gravely traumatised, meaning 1.5 million people.

Effectively, they expect between 10% and 40% of the city to be essentially destroyed.

Istanbul's long history as the capital of two empires before becoming the biggest city in modern Turkey means there is a wealth of historical data on earthquakes. Scientists have combed the records going back 1,500 years, establishing that the city has suffered "heavy damage" from 12 tremors The North Anatolian fault, one of the most active seismic zones in the world, runs within a few miles of the city under the Sea of Marmara. Since the disastrous Erzincan earthquake in December 1939 in eastern Turkey, there have been six earthquakes along the fault with a magnitude greater than seven points, all progressing from east to west. The most recent, in 1999, was less than 60 miles east of Istanbul.