Thanks, John.
Bernie
>Bernie's recording of the Kelso Dune is now posted in the group's Files.
>
>http://groups.yahoo.com/group/naturerecordists/files/Dunes4.mp3
>
>For some reason Yahoo wouldn't recognize Bernie's file when he tried
>to upload it, so I offered to post it for him.
>-John Hartog
>
>
>--- In Wild Sanctuary <>
>wrote:
>> Dunesong is something we worked on with a group from UC Santa Cruz
>> for about 7 years in the 90s as part of a team headed by the late Ken
>> Norris (the fellow who discovered how dolphins echolocate and who was
>> head of the Environmental Studies Dept, there). The team consisted of
>> a nuclear physicist, several geologists, two naturalists, and a
>> storyteller (for our evening campsites).
>>
>> Studies of dunesong were first initiated by Bagnole in the mid-50s
>> and have been going on ever since, however intermittently. There are
>> several literary references to dunesong in T. E. Lawrence's (Lawrence
>> of Arabia) writings. Native Americans of the southwest have ancient
>> myths that tell of the spirits hiding in the desert that speak to
>> them at certain times and sites. Dunesong, because it is very low
>> frequency, can often be heard 7 - 8 miles (11 - 13km) from the point
>> of origin if the weather conditions are right.
>>
>> We measured 10 different sites in the West and Southwest (Nevada,
>> California, Arizona, N. Mexico and Colorado). No one knows for sure
>> what's happening since not all dunes "sing" and those that do, do not
>> do it all the time. After measuring sand grain size, shape, angle of
>> repose (of the slipface of the dune), surface and depth temperatures,
>> accumulated moisture at different layers, and magnetite content, we
>> figured that when certain grain size, shape, and magnetite and
>> moisture create ideal conditions for dunes to "sing," they begin to
>> resonate. Sometimes they "tire" and have to recharge before "singing"
>> again.
>>
>> Typically, when conditions are right, a drier layer moves slowly over
>> a more humid layer, which, in turn is moving at a slightly faster
>> rate than the one below it. Each layer forms ridges as it moves
>> downward. No one knows for sure if the movement (friction) over the
>> ridges (wave forms of a physical type) causes resonance. But some of
>> us think it does assuming all other conditions conspire.
>>
>> Two ways dunesong can be introduced: (1) naturally, when the angle of
>> repose and other conditions are just right and assuming the dune is a
>> "singer," and (2) by climbing all the way up to the top of the dune
>> ridge and sliding down on your ass. Dunesong sounds more like a
>> freight train to me - having none of the hi-freq of a jet - and can
>> last anywhere from a few seconds to over three minutes. They range
>> from infrasound (in the 5Hz range) to around 120Hz and each dune
>> seems to have it's own range of signatures unique to that site.
>>
>> I've got a good example of Kelso singing if someone will walk me thru
>> the process of how to post it.
>>
>> Bernie Krause
>>
>> > >To the north about 10 miles are the Kelso Dunes, one of the
>> >>sites in the desert SW where you can record the dunes singing
>> >>assuming conditions are right and you have the right transducers (a
>> >>pair of good PZM mics or hydrophones in ziploc bags of water buried
>> >>in the sand in order to get the infrasound component at around 10Hz).
>> >>Best window to record is between late March and May. There's also a
>> >>National Park Service visitor center north of the dunes on the
>> >>Kelbaker Rd at Kelso where we've just installed a couple of
>> >>soundscapes representing the desert in that area. It is scheduled to
>> >>be open sometime in August of this year.
>> >
>> >I visited the Kelso Dunes on my way back from recording at Joshua
>> >Tree National Park a couple of weeks ago. I climbed most of the way
>> >up the big dune, but they weren't sayin' anything. What are the
> > >conditions that produce singing?
>> >
>> >BTW the interpretive sign said it sounded like an airplane. I heard
>> >several of those, but I wasn't fooled.
>> >
>> >-Dan Dugan
>> >
>> >
>> >"Microphones are not ears,
>> >Loudspeakers are not birds,
>> >A listening room is not nature."
>> >Klas Strandberg
>> >Yahoo! Groups Links
>> >
>> >
>> >
>> >
>>
>>
>> --
>> Wild Sanctuary
>> P. O. Box 536
>> Glen Ellen, CA 95442
>> t. 707-996-6677
>> f. 707-996-0280
>> http://www.wildsanctuary.com
>
>
>
>
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>Yahoo! Groups Links
>
>
>
>
--
Wild Sanctuary
P. O. Box 536
Glen Ellen, CA 95442
t. 707-996-6677
f. 707-996-0280
http://www.wildsanctuary.com
________________________________________________________________________
________________________________________________________________________
|