Sure. It's at http://wwwneic.cr.usgs.gov/neis/bulletin/neic_tmbc.html
Malcolm McClure
On 21 Jan 2005, at 18:39, Turner, Joshua C wrote:
> I can't find the listing in the USGS for this one yet, but I suspect
> most of their range of uncertainty is generally in the horizontal
> scale. The depth usually says it's fixed by program algorithm. Maybe
> you can share press release?
> Josh
>
> -----Original Message-----
> From: Tectonics & structural geology discussion list on behalf of
> Malcolm McClure
> Sent: Fri 1/21/2005 12:31 PM
> To: [log in to unmask]
> Cc:
> Subject: Re: RE : Earthquake
>
> Now we are discussing something really interesting. There was a 5.4 in
> the Nicobar islands yesterday (happens in UK on average every 8 years).
> USGS says depth was 26.9 km., plus or minus 27.2 km. The upper limit
> for this earthquake was apparently about 300 metres above sea level.
> Can someone please explain?
>
> Malcolm McClure
> On 21 Jan 2005, at 17:45, Musson, Roger MW wrote:
>
>> Actually aftershocks seldom if ever produce tsunamis. Either they are
>> too small, or in the case where a tsunami is related to the dislodging
>> of seabed sediment, all the loose stuff has already gone in the main
>> shock.
>>
>> In this case the largest aftershock was 7.3, very soon after the main
>> shock. The rest were 6s at best. The difference in tsunamigenic
>> potential of a 6.5 earthquake with perhaps 20 km length of fault
>> movement, compared to a 9 with 1200 km of rupture, is immense. The
>> critical issue in this disaster is that the main shock was really
>> extraordinarily huge. The way the magnitude scale ascends rather
>> disguises the immensity of a 9 until you start looking at it in other
>> ways (like size of rupture).
>>
>> Roger Musson
>>
>> British Geological Survey
>> West Mains Road
>> Edinburgh EH9 2NA
>> Scotland
>>
>> tel:+44-(0)131-650-0205
>> fax:+44-(0)131-667-1877
>> email: [log in to unmask]
>>
>>> -----Original Message-----
>>> From: Tectonics & structural geology discussion list
>>> [mailto:[log in to unmask]]On Behalf Of Malcolm McClure
>>> Sent: 21 January 2005 17:33
>>> To: [log in to unmask]
>>> Subject: RE : Earthquake
>>>
>>>
>>> Sad, really, that when 250,000 people die as a result of a tectonic
>>> disturbance, the assembled leading world's experts on tectonics can
>>> tell us how many angels can dance on the head of a pin, but
>>> still can't
>>> explain why the 9.0 produced a tsunami but several major aftershocks,
>>> all along the faultline didn't, apparently, produce mini-tsunamis.
>>>
>>> Malcolm McClure
>>>
>>
>>
>> *********************************************************************
>> This e-mail message, and any files transmitted with it, are
>> confidential and intended solely for the use of the addressee.
>> However, the information contained in this e-mail may subsequently be
>> subject to public disclosure under the Freedom of Information Act 2000
>> and, unless the information is legally exempt from disclosure, the
>> confidentially of this e-mail and your reply cannot be guaranteed. If
>> this message was not intended for you, you have received it in error
>> and any copying, distribution or other use of any part of it is
>> strictly prohibited. Any views or opinions presented are solely those
>> of the sender and do not necessarily represent those of the British
>> Geological Survey. The security of e-mail communication cannot be
>> guaranteed and the BGS accepts no liability for claims arising as a
>> result of the use of this medium to transmit messages from or to the
>> BGS. http://www.bgs.ac.uk
>> *********************************************************************
>>
>
|