Thins quite interesting study determined that the source of a set of very long period (VLP), long duration seismic signals detected over several different continents were caused by the drainage of a deep magma basin near Mayotte, in the Indian Ocean. The reservoir is some 10 to 15 km wide, 20 to 25 km deep. Some 1300 gigalitres of magma has drained.

Drainage of deep magma reservoir near Mayotte inferred

This is kind of big news in terms of understanding the causes of VLP signals.

Unfortunately it has been somewhat misrepresented in the general news.
https://edition.cnn.com/2020/01/09/world/seismic-hum-volcano-scn-trnd/index.html
Origin of mystery humming noises heard around the world, uncovered

In 2018, a multitude of seismic signals were detected by earthquake monitoring agencies all over the world in May and June. They created a weird humming sound and some of the signals detected in November of that year had a duration of up to 20 minutes.

The signals and humming triggered “the curiosity of the scientific community,” according to a new study that explains what happened: the formation of a new underwater volcano.

I think to a lay reader, the implication here would be that this was actually a humming noise that humans were hearing, particularly as they imply the very long period seismic signals and the “humming” are two separate phenomena by saying “the signals and the humming”.

The signals here have a period of about 15 seconds, ie a frequency of about 0.07 Hz. The lowest sound a human can hear, under the best conditions, is around 18 Hz. We can feel vibrations a bit lower in frequency than that, but certainly nothing near the range of these VLP signals.

dv said:

Thins quite interesting study determined that the source of a set of very long period (VLP), long duration seismic signals detected over several different continents were caused by the drainage of a deep magma basin near Mayotte, in the Indian Ocean. The reservoir is some 10 to 15 km wide, 20 to 25 km deep. Some 1300 gigalitres of magma has drained.

Drainage of deep magma reservoir near Mayotte inferred

This is kind of big news in terms of understanding the causes of VLP signals.

Unfortunately it has been somewhat misrepresented in the general news.
https://edition.cnn.com/2020/01/09/world/seismic-hum-volcano-scn-trnd/index.html
Origin of mystery humming noises heard around the world, uncovered

In 2018, a multitude of seismic signals were detected by earthquake monitoring agencies all over the world in May and June. They created a weird humming sound and some of the signals detected in November of that year had a duration of up to 20 minutes.

The signals and humming triggered “the curiosity of the scientific community,” according to a new study that explains what happened: the formation of a new underwater volcano.

I think to a lay reader, the implication here would be that this was actually a humming noise that humans were hearing, particularly as they imply the very long period seismic signals and the “humming” are two separate phenomena by saying “the signals and the humming”.

The signals here have a period of about 15 seconds, ie a frequency of about 0.07 Hz. The lowest sound a human can hear, under the best conditions, is around 18 Hz. We can feel vibrations a bit lower in frequency than that, but certainly nothing near the range of these VLP signals.

If someone stood behind me and hit me with a hammer in a periodic fashion every 15 seconds I think I would feel it.

it’s like that myth primary school kids used to spread, that you can feel continental drift

sibeen said:

dv said:

Thins quite interesting study determined that the source of a set of very long period (VLP), long duration seismic signals detected over several different continents were caused by the drainage of a deep magma basin near Mayotte, in the Indian Ocean. The reservoir is some 10 to 15 km wide, 20 to 25 km deep. Some 1300 gigalitres of magma has drained.

Drainage of deep magma reservoir near Mayotte inferred

This is kind of big news in terms of understanding the causes of VLP signals.

Unfortunately it has been somewhat misrepresented in the general news.
https://edition.cnn.com/2020/01/09/world/seismic-hum-volcano-scn-trnd/index.html
Origin of mystery humming noises heard around the world, uncovered

In 2018, a multitude of seismic signals were detected by earthquake monitoring agencies all over the world in May and June. They created a weird humming sound and some of the signals detected in November of that year had a duration of up to 20 minutes.

The signals and humming triggered “the curiosity of the scientific community,” according to a new study that explains what happened: the formation of a new underwater volcano.

I think to a lay reader, the implication here would be that this was actually a humming noise that humans were hearing, particularly as they imply the very long period seismic signals and the “humming” are two separate phenomena by saying “the signals and the humming”.

The signals here have a period of about 15 seconds, ie a frequency of about 0.07 Hz. The lowest sound a human can hear, under the best conditions, is around 18 Hz. We can feel vibrations a bit lower in frequency than that, but certainly nothing near the range of these VLP signals.

If someone stood behind me and hit me with a hammer in a periodic fashion every 15 seconds I think I would feel it.

And you’d be a rapper

SCIENCE said:

it’s like that myth primary school kids used to spread, that you can feel continental drift

What sort of high-falutin primary school did you attend?

sibeen said:

dv said:

Thins quite interesting study determined that the source of a set of very long period (VLP), long duration seismic signals detected over several different continents were caused by the drainage of a deep magma basin near Mayotte, in the Indian Ocean. The reservoir is some 10 to 15 km wide, 20 to 25 km deep. Some 1300 gigalitres of magma has drained.

Drainage of deep magma reservoir near Mayotte inferred

This is kind of big news in terms of understanding the causes of VLP signals.

Unfortunately it has been somewhat misrepresented in the general news.
https://edition.cnn.com/2020/01/09/world/seismic-hum-volcano-scn-trnd/index.html
Origin of mystery humming noises heard around the world, uncovered

In 2018, a multitude of seismic signals were detected by earthquake monitoring agencies all over the world in May and June. They created a weird humming sound and some of the signals detected in November of that year had a duration of up to 20 minutes.

The signals and humming triggered “the curiosity of the scientific community,” according to a new study that explains what happened: the formation of a new underwater volcano.

I think to a lay reader, the implication here would be that this was actually a humming noise that humans were hearing, particularly as they imply the very long period seismic signals and the “humming” are two separate phenomena by saying “the signals and the humming”.

The signals here have a period of about 15 seconds, ie a frequency of about 0.07 Hz. The lowest sound a human can hear, under the best conditions, is around 18 Hz. We can feel vibrations a bit lower in frequency than that, but certainly nothing near the range of these VLP signals.

If someone stood behind me and hit me with a hammer in a periodic fashion every 15 seconds I think I would feel it.

That’s not what is meant in this case. The Fourier spectrum of repeated blows to the head every 15 seconds would be broad, including some very high frequencies.

dv said:

sibeen said:

dv said:

Thins quite interesting study determined that the source of a set of very long period (VLP), long duration seismic signals detected over several different continents were caused by the drainage of a deep magma basin near Mayotte, in the Indian Ocean. The reservoir is some 10 to 15 km wide, 20 to 25 km deep. Some 1300 gigalitres of magma has drained.

Drainage of deep magma reservoir near Mayotte inferred

This is kind of big news in terms of understanding the causes of VLP signals.

Unfortunately it has been somewhat misrepresented in the general news.
https://edition.cnn.com/2020/01/09/world/seismic-hum-volcano-scn-trnd/index.html
Origin of mystery humming noises heard around the world, uncovered

In 2018, a multitude of seismic signals were detected by earthquake monitoring agencies all over the world in May and June. They created a weird humming sound and some of the signals detected in November of that year had a duration of up to 20 minutes.

The signals and humming triggered “the curiosity of the scientific community,” according to a new study that explains what happened: the formation of a new underwater volcano.

I think to a lay reader, the implication here would be that this was actually a humming noise that humans were hearing, particularly as they imply the very long period seismic signals and the “humming” are two separate phenomena by saying “the signals and the humming”.

The signals here have a period of about 15 seconds, ie a frequency of about 0.07 Hz. The lowest sound a human can hear, under the best conditions, is around 18 Hz. We can feel vibrations a bit lower in frequency than that, but certainly nothing near the range of these VLP signals.

If someone stood behind me and hit me with a hammer in a periodic fashion every 15 seconds I think I would feel it.

That’s not what is meant in this case. The Fourier spectrum of repeated blows to the head every 15 seconds would be broad, including some very high frequencies.

OK, if I stood on a boat with waves passing at a frequency of 0.07 Hz, I would feel it unless they were very small waves.

dv said:

sibeen said:

dv said:

Thins quite interesting study determined that the source of a set of very long period (VLP), long duration seismic signals detected over several different continents were caused by the drainage of a deep magma basin near Mayotte, in the Indian Ocean. The reservoir is some 10 to 15 km wide, 20 to 25 km deep. Some 1300 gigalitres of magma has drained.

Drainage of deep magma reservoir near Mayotte inferred

This is kind of big news in terms of understanding the causes of VLP signals.

Unfortunately it has been somewhat misrepresented in the general news.
https://edition.cnn.com/2020/01/09/world/seismic-hum-volcano-scn-trnd/index.html
Origin of mystery humming noises heard around the world, uncovered

In 2018, a multitude of seismic signals were detected by earthquake monitoring agencies all over the world in May and June. They created a weird humming sound and some of the signals detected in November of that year had a duration of up to 20 minutes.

The signals and humming triggered “the curiosity of the scientific community,” according to a new study that explains what happened: the formation of a new underwater volcano.

I think to a lay reader, the implication here would be that this was actually a humming noise that humans were hearing, particularly as they imply the very long period seismic signals and the “humming” are two separate phenomena by saying “the signals and the humming”.

The signals here have a period of about 15 seconds, ie a frequency of about 0.07 Hz. The lowest sound a human can hear, under the best conditions, is around 18 Hz. We can feel vibrations a bit lower in frequency than that, but certainly nothing near the range of these VLP signals.

If someone stood behind me and hit me with a hammer in a periodic fashion every 15 seconds I think I would feel it.

That’s not what is meant in this case. The Fourier spectrum of repeated blows to the head every 15 seconds would be broad, including some very high frequencies.

That would be me screaming.

The Rev Dodgson said:

dv said:

sibeen said:

If someone stood behind me and hit me with a hammer in a periodic fashion every 15 seconds I think I would feel it.

That’s not what is meant in this case. The Fourier spectrum of repeated blows to the head every 15 seconds would be broad, including some very high frequencies.

OK, if I stood on a boat with waves passing at a frequency of 0.07 Hz, I would feel it unless they were very small waves.

So it’s amplitude rather than frequency?

Tamb said:

The Rev Dodgson said:

dv said:

That’s not what is meant in this case. The Fourier spectrum of repeated blows to the head every 15 seconds would be broad, including some very high frequencies.

OK, if I stood on a boat with waves passing at a frequency of 0.07 Hz, I would feel it unless they were very small waves.

So it’s amplitude rather than frequency?

A combination.

You’d never feel 0.07 Hz if they had the amplitude of sound waves, but you can hear sound waves.

The Rev Dodgson said:

Tamb said:

The Rev Dodgson said:

OK, if I stood on a boat with waves passing at a frequency of 0.07 Hz, I would feel it unless they were very small waves.

So it’s amplitude rather than frequency?

A combination.

You’d never feel 0.07 Hz if they had the amplitude of sound waves, but you can hear sound waves.

That’s a good explanation. Ta.

dv said:

Thins quite interesting study determined that the source of a set of very long period (VLP), long duration seismic signals detected over several different continents were caused by the drainage of a deep magma basin near Mayotte, in the Indian Ocean. The reservoir is some 10 to 15 km wide, 20 to 25 km deep. Some 1300 gigalitres of magma has drained.

Drainage of deep magma reservoir near Mayotte inferred

This is kind of big news in terms of understanding the causes of VLP signals.

Unfortunately it has been somewhat misrepresented in the general news.
https://edition.cnn.com/2020/01/09/world/seismic-hum-volcano-scn-trnd/index.html
Origin of mystery humming noises heard around the world, uncovered

In 2018, a multitude of seismic signals were detected by earthquake monitoring agencies all over the world in May and June. They created a weird humming sound and some of the signals detected in November of that year had a duration of up to 20 minutes.

The signals and humming triggered “the curiosity of the scientific community,” according to a new study that explains what happened: the formation of a new underwater volcano.

I think to a lay reader, the implication here would be that this was actually a humming noise that humans were hearing, particularly as they imply the very long period seismic signals and the “humming” are two separate phenomena by saying “the signals and the humming”.

The signals here have a period of about 15 seconds, ie a frequency of about 0.07 Hz. The lowest sound a human can hear, under the best conditions, is around 18 Hz. We can feel vibrations a bit lower in frequency than that, but certainly nothing near the range of these VLP signals.

Thanks for that dv. Interesting paper.

I read another paper (in Geology?) about the crustal deflation and the submarine volcano development last year. This links the events nicely.

dv said:

Thins quite interesting study determined that the source of a set of very long period (VLP), long duration seismic signals detected over several different continents were caused by the drainage of a deep magma basin near Mayotte, in the Indian Ocean. The reservoir is some 10 to 15 km wide, 20 to 25 km deep. Some 1300 gigalitres of magma has drained.

Drainage of deep magma reservoir near Mayotte inferred

This is kind of big news in terms of understanding the causes of VLP signals.

Unfortunately it has been somewhat misrepresented in the general news.
https://edition.cnn.com/2020/01/09/world/seismic-hum-volcano-scn-trnd/index.html
Origin of mystery humming noises heard around the world, uncovered

In 2018, a multitude of seismic signals were detected by earthquake monitoring agencies all over the world in May and June. They created a weird humming sound and some of the signals detected in November of that year had a duration of up to 20 minutes.

The signals and humming triggered “the curiosity of the scientific community,” according to a new study that explains what happened: the formation of a new underwater volcano.

I think to a lay reader, the implication here would be that this was actually a humming noise that humans were hearing, particularly as they imply the very long period seismic signals and the “humming” are two separate phenomena by saying “the signals and the humming”.

The signals here have a period of about 15 seconds, ie a frequency of about 0.07 Hz. The lowest sound a human can hear, under the best conditions, is around 18 Hz. We can feel vibrations a bit lower in frequency than that, but certainly nothing near the range of these VLP signals.

Thanks, that’s very informative. Yeah, deep magma motion has been noted before, eg. under Yellowstone. I understand that Mayotte is a very special case. I’m trying to remember why.

Some long period seismic humming has been observed to be due to ocean currents, and IIRC even due to movements in the atmosphere.