
Seismic waves reveal giant structures deep beneath Earth's surface - rbanffy
https://www.newscientist.com/article/2245939-seismic-waves-reveal-giant-structures-deep-beneath-earths-surface/
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jl6
> The shear wave echoes from a single seismogram are difficult to distinguish
> from random noise, so the researchers used a machine-learning algorithm
> originally designed for identifying trends in large astronomy data sets.

How does one convince oneself that such a machine-learning algorithm is
finding genuine signal in the noise, rather than just generating echoes of its
training data?

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aaron695
I asked this question if it really was Machine Learning last time this was
posted and I don't think it was (Feel free to correct me)

It's - [http://sequencer.org/](http://sequencer.org/)

Pseudo-code -
[http://sequencer.org/static/images/image1.png](http://sequencer.org/static/images/image1.png)

I find it much more exciting than ML because it's both real and seems to be a
simple online service for scientists, which is pretty cool.

A video on it -
[https://www.youtube.com/watch?v=KN-N7l5spmE](https://www.youtube.com/watch?v=KN-N7l5spmE)

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mturmon
On a cursory look it seems to construct a distance matrix between all pairs of
items, and look for a spanning tree with that distance metric that is
"elongated" \- i.e., less branching. Straightforward enough.

There seems to be a bit more, involving iterating over different scales and
over different distance metrics, but that's not particularly principled or
efficient.

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based2
[https://en.wikipedia.org/wiki/Phlegraean_Fields](https://en.wikipedia.org/wiki/Phlegraean_Fields)

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mirimir
Does lower S-wave velocity imply high-viscosity liquid?

And might that be due to water? Maybe oceanic crust carried by deep
convection?

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sideshowb
Creatures moving through solid rock...

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airstrike
The Devil in the Dark?

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sideshowb
Sorry I can't remember! I was thinking of a short story by either Clarke or
Asimov

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redis_mlc
I blame the Mayans.

