I am a earthquake seismologist. AMA. 5th anniversary of Louisa Quake

[Anonymous]

My DH has felt tremors from 5 earthquakes. What are the chances of that?

[Anonymous]

Anonymous wrote:My DH has felt tremors from 5 earthquakes. What are the chances of that?

If he was in California or an earthquake prone area then the chances are high, obviously. Duh.

[Anonymous]

Anonymous wrote:Any predictions for the next year or so? Where will be the next big one?

There is no valid method for predicting earthquakes. The current state of the art on earthquakes is that the source is random...the in some cases, the small earthquake will not stop for a while, and grows to be a big earthquake. In other cases (most cases) it stops.

[Anonymous]

Anonymous wrote:My DH has felt tremors from 5 earthquakes. What are the chances of that?

Even in Northern VA, I felt shaking from 7 earthquakes since I lived hear. It is not surprising.

[Anonymous]

Why not talk about the ones in Italy and Myanmar? I don't recall seeing two 6 plus earthquakes in separate parts of the world on the same day.

[Anonymous]

Could the high death toll in Amatrice have been avoided today?

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:This is the first I knew that the earthquake had the name "Louisa." Who gave it that name and are all earthquakes given names? Are they all female, or do they now alternate between male in female names like hurricanes.

Earthquakes are named for the source location. Tohuku was the 2011 Japan earthquake. Sumatra-andaman Islands was the 2004 Boxing day earthquake.

Louisa is the county where the 2011 VA earthquake was centered. The naming is informal, and can change depending on the context. For example, the 1989 Loma Prieta earthquake is called that because of where it happened. But when talking to the public, most people now refer to it as the World Series Earthquake.

I'm from the bay area and I've never heard anyone call it the World Series Earthquake. I've heard people call it the Loma Prieta earthquake, the 1989 earthquake, or just the earthquake (people who were there would know to which you refer).

In the bay area, people know about Loma Prieta earthquake name. But, I go out in public talking, and mention a story relating Loma Prieta, I will get something like Huh? If I say World Series Earthquake, people know what I am talking about. This is true of others too.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:I grew up in what is now Serbia, but we had lots of Earthquakes all over former eastern parts of Yugoslavia. Why were there so many earthquakes there in the 1970s and even 80s and now there are hardly any? I didn't think it was near tectonic plates. We would have like "sliding" effect if you were sitting on a couch and earthquake happened.

Are there mountains in Serbia (I believe the answer is yes). Mountains that are growing means something is pushing the crust. That deformation, which forms the mountains, also is the driving force for earthquakes.

Tell us something we can't look up on wiki. All of the info you've posted so far seems very basic and common knowledge.

What is your actual job that you do and what do you know that we can't get off a recent wtop or slate article?

I am just answering the questions. I do not know everything about every region.

I didn't ask anything about a specific region. I asked you to tell us what your actual job is and to tell us something we can't get from an ordinary FB post by IFLS. Please.

My job -- I can not talk about all of it. But, in general, I get data from remote sites, analyze it, and try to figure out what the data means. Specifically, what caused the signal that is being observed on the seismic sensor: was it an Earthquake? Explosion? or something more exotic. Much of my work today is spent on automating the process.

[Anonymous]

Anonymous wrote:Could the high death toll in Amatrice have been avoided today?

Possibly. 6.2 is not that big; earthquake resistant building, for example, would help. I have not really looked at anything related to that earthquake (I had medical tests the AM, and just finished that up).

A good way to look at this is to go to 2010. Two earthquakes, a 7.1 in Haiti, and an 8.8 in Chile occurred 6 weeks apart. The Chilean event was about 100x bigger than the Haiti earthquake, but had very few casualties. Why? Building codes. By comparison, the smaller Haitian earthquake hit in a poor city with no building codes; possibly over 200,000 people were killed. Building codes and code enforcement matter.

[Anonymous]

Anonymous wrote:Why not talk about the ones in Italy and Myanmar? I don't recall seeing two 6 plus earthquakes in separate parts of the world on the same day.

It happens frequently. several times in the last month, based on the USGS catalog. In the past year, there were 148 Magnitude 6+ earthquakes globally. That means, close to every other day. If they are random, in a given year, you would expect 23 days per year to have multiple M>= 6 earthquakes, assuming 100% random distribution.

(for matlab people, here is how I came up with that:

for i=1:1000
doy=round(rand(148,1)*365);
[n,b]=hist(doy,0:365);
nx(i)=sum(n>1);
end
mean(nx)
ans =

22.8470

[Anonymous]

What happens at 2:45? An earthquake?

[Anonymous]

Anonymous wrote:

Anonymous wrote:Why not talk about the ones in Italy and Myanmar? I don't recall seeing two 6 plus earthquakes in separate parts of the world on the same day.

It happens frequently. several times in the last month, based on the USGS catalog. In the past year, there were 148 Magnitude 6+ earthquakes globally. That means, close to every other day. If they are random, in a given year, you would expect 23 days per year to have multiple M>= 6 earthquakes, assuming 100% random distribution.

(for matlab people, here is how I came up with that:

for i=1:1000
doy=round(rand(148,1)*365);
[n,b]=hist(doy,0:365);
nx(i)=sum(n>1);
end
mean(nx)
ans =

22.8470

Point taken. And most would be epic entered undersea or unpopulated land. My question was more oriented to significant damage and death.

[Anonymous]

Anonymous wrote:What happens at 2:45? An earthquake?

I don't know. I was asleep.

[Anonymous]

Matlab. Good times.

So is a seismologist respected in the DOD world?

Do you ever want to live/work in a different region/industry? Academia?

[Anonymous]

Anonymous wrote:Why not talk about the ones in Italy and Myanmar? I don't recall seeing two 6 plus earthquakes in separate parts of the world on the same day.

Because the author of this thread is a troll and doesn't know any technical info.