What is "poorly constrained"?

I have found this term about earthquakes and I don't understand what it means or how can be defined in one phrase.

I tried to give a definition:

Poorly constrained is an earthquake with the hypocenter ≥ epicenter a shallow earthquake where Pp-P=0 if P=S with a high area of spreading of the seismic waves that is creating multiple points of in depth location.

and USGS

earthquake.usgs.gov...

Any help please?

reply to post by piequal3because14


Poorly constrained in this case means that the multiple measured points are not confined to one particular location, and they can't really determine the exact epicenter.

I think.

Originally posted by WoodSpirit
reply to post by piequal3because14

 

Poorly constrained in this case means that the multiple measured points are not confined to one particular location, and they can't really determine the exact epicenter.

I think.

edit on 14-11-2012 by WoodSpirit because: (no reason given)

It can be I don't know

with many answers maybe we can make a vision about this term and how it can be defined.

reply to post by piequal3because14


It can't be much else, now can it?

con·strain (kn-strn) tr.v. con·strained, con·strain·ing, con·strains
1. To compel by physical, moral, or circumstantial force; oblige: felt constrained to object. See Synonyms at force.
2. To keep within close bounds; confine: a life that had been constrained by habit to the same few activities and friends.
3. To inhibit or restrain; hold back: "Failing to control the growth of international debt will also constrain living standards" (Ronald Brownstein).
4. To produce in a forced or inhibited manner.

We're obviously talking about this one,

2. To keep within close bounds; confine:

reply to post by WoodSpirit

It cant be much else can it?

Oh yes,very complicated with these earthquakes.

reply to post by piequal3because14


Semantics and reading comprehension are pretty tough too.

Sometimes when depth is poorly constrained by available seismic data, the location program will set the depth at a fixed value.

When their measurements are poorly constrained, they are not bound to one location but all over the place, and they can't determine the exact depth.

It's really quite obvious what it means.

reply to post by WoodSpirit

When their measurements are poorly constrained, they are not bound to one location but all over the place, and they can't determine the exact depth.

I thought there are and other parameters involved.

Semantics and reading comprehension are pretty tough too.

That is why I asked this question about what a "poorly constrained" earthquake is.

Thank you for you kind answer and explanation.

reply to post by piequal3because14


In English it means "We have not got a blooming clue" but yes what the others have said is right - the depth, or whatever measurement cannot be accurately determined from the data to a reasonable degree of accuracy.

The USGS says:

Sometimes when depth is poorly constrained by available seismic data, the location program will set the depth at a fixed value. For example, 33 km is often used as a default depth for earthquakes determined to be shallow, but whose depth is not satisfactorily determined by the data, whereas default depths of 5 or 10 km are often used in mid-continental areas and on mid-ocean ridges since earthquakes in these areas are usually shallower than 33 km.

Emphasis by me.

reply to post by PuterMan

In English it means "We have not got a blooming clue" but yes what the others have said is right - the depth, or whatever measurement cannot be accurately determined from the data to a reasonable degree of accuracy.

Oh, you mean like 'Um, we don't really know'.

I never thought of that.

Very interesting explanation and thank you for it.