NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

Roll & Rock

21338

Date: April 05, 2020 at 17:55:13
From: Mikhail, [DNS_Address]
Subject: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

PREDICTED TIME: Tuesday, Apr. 14, 2020, Noon Pacific
Daylight Time, plus or minus 72 hours. Mainshock
only, aftershocks are irrelevant to this prediction.

PREDICTED MAGNITUDE: 6.2 - 6.6 (moment magnitude,
USGS)

PREDICTED LOCATION: Within California north of
36 degrees N. (including offshore to edge of
continent)

PROBABILITY of hitting all parameters by random
coincidence:

<0.5% based on 100-year EQ history
(~1 in 250 odds of success)

NO CONFIDENCE LEVEL PROVIDED -- INSUFFICIENT TRACK
RECORD.

Responses:
[21397] [21398] [21401] [21402] [21403] [21406] [21407] [21408] [21411] [21412] [21413] [21414] [21415] [21416] [21417] [21418] [21419] [21422] [21420] [21421] [21399] [21400] [21367] [21368] [21339] [21340] [21341] [21342] [21343] [21344] [21345] [21346] [21347] [21348] [21351] [21352] [21353] [21349] [21354] [21350]

21397

Date: May 15, 2020 at 09:00:55
From: Mikhail, [DNS_Address]
Subject: HIT mag. MISS by 20 miles and 28 days

Close but no сигара.

Rare event:
M6.5 this morning near Tonapah NV.

Missed location (NorCal) by 20 miles.
Missed time by 28 days.
HIT narrow magnitude range.

Perhaps the M5.2 near Bodie, CA, on April 18 (a miss
on time and mag) was a foreshock?

Responses:
[21398] [21401] [21402] [21403] [21406] [21407] [21408] [21411] [21412] [21413] [21414] [21415] [21416] [21417] [21418] [21419] [21422] [21420] [21421] [21399] [21400]

21398

Date: May 15, 2020 at 12:53:40
From: Roger Hunter, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

You and Amit, clutching at straws.

What possible use is a prediction that misses by 28
days?

but it can do a LOT of harm.

Roger

Responses:
[21401] [21402] [21403] [21406] [21407] [21408] [21411] [21412] [21413] [21414] [21415] [21416] [21417] [21418] [21419] [21422] [21420] [21421] [21399] [21400]

21401

Date: May 16, 2020 at 00:27:01
From: Mikhail, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

"What possible use is a prediction that misses by 28
days?"

1. Assessing the distance between theory and
practice, thereby serving as a “reality check” to
the relevance of theories. In short, hypothesis
building and testing.

2. Goading the skeptical heart into pumping a few more
waning cycles.

Responses:
[21402] [21403] [21406] [21407] [21408] [21411] [21412] [21413] [21414] [21415] [21416] [21417] [21418] [21419] [21422] [21420] [21421]

21402

Date: May 16, 2020 at 12:01:49
From: Roger Hunter, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

Mikhail;

I agree that methods must be tested and revised but
hypothesis testing should not be presented as real
predictions.

Actually, such testing should be done in private to
prevent misunderstandings.

I'm working on a program to compute probability for
predictions based on various types of input
parameters such as mag ranges, window length, date
ranges, location limits such as lat/lon boxes or
center point/radius.

If anyone is interested in such a program, I'd
appreciate suggestions on what they would find
useful.

Roger

Responses:
[21403] [21406] [21407] [21408] [21411] [21412] [21413] [21414] [21415] [21416] [21417] [21418] [21419] [21422] [21420] [21421]

21403

Date: May 16, 2020 at 12:06:40
From: Roger Hunter, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

I can guarantee right now based on preliminary testing
that the probability of a mag 6+ quake in a 28 day
window is 1.000

Roger

Responses:
[21406] [21407] [21408] [21411] [21412] [21413] [21414] [21415] [21416] [21417] [21418] [21419] [21422] [21420] [21421]

21406

Date: May 16, 2020 at 18:26:21
From: Mikhail, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

Excuse me. Let's keep it real. You violated your own
rule! You failed to specify a geographic window for
your claim that "the probability of a mag 6+ quake
in a 28 day window is 1.000".

Just so everybody's clear--you're not
insinuating a 1.0 probability over 28 days for a M6+
event in the geographic window that I specified
(NorCal) in my M6.4 +/- 0.2 prediction. Right?

If NorCal is the area you implied, then your
program needs a bit more work. The USGS shows 32 M6+
events in that defined area since 1900 (1,564 28-day
periods) = 0.02 probability in a 28-day window.

(Granted, some M6+ quakes there weren't
detected/reported in unpopulated parts of the state
during the first half of the 20th century, so the
probability might be a tittle higher. But
eliminating aftershocks would make it lower.)

Responses:
[21407] [21408] [21411] [21412] [21413] [21414] [21415] [21416] [21417] [21418] [21419] [21422] [21420] [21421]

21407

Date: May 16, 2020 at 18:41:39
From: Roger Hunter, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

Mikhail;

You're right. That calculation was for a 28 day window
and a mag 6+ quake, location not specified.

just testing the program.

I'll redo it for his window.

Stand by...

Roger

Responses:
[21408] [21411] [21412] [21413] [21414] [21415] [21416] [21417] [21418] [21419] [21422] [21420] [21421]

21408

Date: May 16, 2020 at 19:08:08
From: Roger Hunter, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

Mikhail;

Thank you! I had been struggling with that program for
several days so when I finally found that error I
thought I was done. Failing to note that the program
was not complete. It was only testing for date and the
wrong date at that!

I appreciate your assistance very much.

More later.

Roger

Responses:
[21411] [21412] [21413] [21414] [21415] [21416] [21417] [21418] [21419] [21422] [21420] [21421]

21411

Date: May 17, 2020 at 07:43:31
From: Mikhail, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

нет проблем. Perhaps "such testing should be done in
private to prevent misunderstandings" for faulty
probabilities "can do a LOT of harm." (Sorry. Woke
up on the snarky side of the bed this morning. :-)

In good faith, one humble mea culpa deserves
another. In my M6.5 prediction I failed to include
my usual disclaimer:

This is a research-grade prediction
only for the purpose of hypothesis testing. The data
on which it is based do not warrant its use as, nor
is it intended to be, a public warning.

Responses:
[21412] [21413] [21414] [21415] [21416] [21417] [21418] [21419] [21422] [21420] [21421]

21412

Date: May 17, 2020 at 10:38:32
From: Roger Hunter, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

Mikhail;

that's a step in the right direction but things like
that should not be made public at all.

They should only be shared with people like me, for
evaluation purposes.

Public release should only be done when reliability
is firmly established, if then.

A better course is to present results to sources of
funding for final polishing and government approval.

Peer reviewed journal publication is one way to do
that but is hard to accomplish without a doctorate
or two.

Roger

Responses:
[21413] [21414] [21415] [21416] [21417] [21418] [21419] [21422] [21420] [21421]

21413

Date: May 17, 2020 at 19:44:09
From: Roger Hunter, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

Mikhail;

Ok, now my test is for a 6.2 to 6.6 quake in the
lat/lon box you specified within 6 day window.

Chances of success are 0.9986

That's a pretty active area.

The test is not for your specific window in time
but with those odds I'd bet on a hit.

Roger

Responses:
[21414] [21415] [21416] [21417] [21418] [21419] [21422] [21420] [21421]

21414

Date: May 17, 2020 at 21:36:07
From: Mikhail, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

You are "clutching at straws" my friend! Either
evaluate the area that I specified or go back to the
drawing board--because your program is still very
wrong.

My prediction explicitly specified northern CA
(including offshore continental area as I defined),
between 36N and the CA-OR border. Being generous for
the purpose of your evaluation, I'll assume you
simplified that irregular area to a rectangular
lat/long box that includes said area, plus a slice
of western NV. This lat/long box was NOT what I
specified, but the magnitude of your error makes
that detail irrelevant.

You claim to test "for a 6.2 to 6.6 quake in the
lat/lon box you [Roger] specified within 6 day
window" finding "Chances of success are 0.9986"
(i.e., near certainty).

You must, of course, realize this means a M6.2-6.6
quake is certain to occur in northern CA on a
WEEKLY basis, on average. Such a large quake
in this area happens only a few times in a career--
the USGS shows fewer than two dozen quakes here in
this size range since 1900 (including Friday's
M6.5).

The true probability you seek (chance of random
success) is almost a thousand times smaller (around
0.001). Try again. Your public test predictions are
probably scaring people. :-)

Responses:
[21415] [21416] [21417] [21418] [21419] [21422] [21420] [21421]

21415

Date: May 18, 2020 at 04:54:48
From: Roger Hunter, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

Mikhail;

I'm using the area bounded by 42 to 36 degrees north
and 119 to 126 degrees west as specified by you, not
me. A 6 day window (+-72 hours), mag 6.2 to 6.6. I
examined all quakes from 1973 to 2020 and that's the
answer that resulted.

Where is the error?

Roger

Responses:
[21416] [21417] [21418] [21419] [21422] [21420] [21421]

21416

Date: May 18, 2020 at 05:19:47
From: Roger Hunter, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

Mikhail;

The error is mine.

A search using the NEIC software turned up a mere
handful of quakes in the specified area, as you
said.

My sincere thanks for pointing this out. There's an
error somewhere, either in my quake file or the
search program.

I'll find it. I hope it's the program. Replacing the
quake file is a monumental effort.

Roger

Responses:
[21417] [21418] [21419] [21422] [21420] [21421]

21417

Date: May 18, 2020 at 06:36:21
From: Roger Hunter, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

Mikhail;

My error indeed!

The odds I was quoting were for a quake on a given day
(every day) anywhere. Probability 1.000

Adding location and mag cut it down to zero. Just as
bad.

Roger

Responses:
[21418] [21419] [21422] [21420] [21421]

21418

Date: May 18, 2020 at 07:18:12
From: Roger Hunter, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

Mikhail;

The neic search turned up 8 quakes in the given area
while my search turned up none.

A manual search of my database found most of the 8
quakes but not in the exact values from the NEIC
search. The differences were largely rounding errors
which would not matter in most cases but computers
tend to expect exact answers. 10 is not 10.001 for
example.

Roger

Responses:
[21419] [21422] [21420] [21421]

21419

Date: May 18, 2020 at 08:33:20
From: Mikhail, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

Thanks, Rog, for further checking your work. And
thanks also for your ruthless skepticism--for there is
no science without it!

Over and out for now (before Bopp brings the hammer
down). Stay safe comrade!

Responses:
[21422] [21420] [21421]

21422

Date: May 18, 2020 at 18:25:58
From: ryan, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

au contraire mon frere...i find it highly entertaining!

Responses:
None

21420

Date: May 18, 2020 at 08:57:05
From: Roger Hunter, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

Adios amigo

Roger

Responses:
[21421]

21421

Date: May 18, 2020 at 15:42:49
From: Roger Hunter, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

Mikhail;

In an effort to discover the truth of the prediction
evaluation I made a number of runs with slight
changes in the parameters.

I found that small changes to the search area made
no difference to the answer but small changes to the
mag limits made a big difference.

If I held the search area to the predicted
boundaries or window size the results were about the
same.

But slight changes to the mag limits made a big
difference particularly changes to the lower limit.
This is to be expected, since there are normally
more small quakes.

The prediction called for a mag range of 6.1 to 6.6
which gave a zero probability but changing it to 6.0
to 6.6 gave odds of 0.246

Roger

Responses:
None

21399

Date: May 15, 2020 at 14:32:42
From: ryan, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

remember, it's a work in progress roger, not a finished product...like windows...

Responses:
[21400]

21400

Date: May 15, 2020 at 16:04:40
From: Roger Hunter, [DNS_Address]
Subject: Re: HIT mag. MISS by 20 miles and 28 days

ryan;

Yes, I know. But evaluation is still required
to understand how well the predictor is doing.

Roger

Responses:
None

21367

Date: April 18, 2020 at 08:00:52
From: Mikhail, [DNS_Address]
Subject: MISS, 1.0 mag too low, 4 h 24 m too early

Mw 5.2 - 30km SE of Bodie, CA; 2020-04-11 14:36:37
(UTC)38.053°N 118.733°W8.5 km depth

(Happy 1906 Anniversary!)

Responses:
[21368]

21368

Date: April 19, 2020 at 10:14:41
From: ryan, [DNS_Address]
Subject: Re: MISS, 1.0 mag too low, 4 h 24 m too early

and yet a good effort mikhail...keep honing...

Responses:
None

21339

Date: April 06, 2020 at 14:48:16
From: Roger Hunter, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

Mikhail;

Could you clarify the location?

Within California and offshore are contradictory,
plus offshore to edge of continent would include a
large chunk of ocean.

Roger

Responses:
[21340] [21341] [21342] [21343] [21344] [21345] [21346] [21347] [21348] [21351] [21352] [21353] [21349] [21354] [21350]

21340

Date: April 06, 2020 at 15:47:39
From: Mikhail, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

Roger, is this satisfactory? WITHIN AREA BOUNDED BY
(A) 42N LATITUDE
(B) California'S EASTERN BORDER
(C) 36N LATITUDE
(D) WESTERN edge of continent DEFINED HEREIN AS THE INTERSECTION ABYSSAL PLAIN WITH
(1) THE CONTINENTAL SLOPE AND
(2) NORTHERN BASE OF THE MENDOCINO ESCARPMENT.

An earthquake nucleating outside that area would be an
unequivocal miss, even if the causative fault ruptures
into that defined area.

Responses:
[21341] [21342] [21343] [21344] [21345] [21346] [21347] [21348] [21351] [21352] [21353] [21349] [21354] [21350]

21341

Date: April 06, 2020 at 17:18:31
From: Roger Hunter, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

Mikhail;

Yes that's much better.

Thank you.

Roger

Responses:
[21342] [21343] [21344] [21345] [21346] [21347] [21348] [21351] [21352] [21353] [21349] [21354] [21350]

21342

Date: April 06, 2020 at 19:33:41
From: Roger Hunter, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

Mikhail;

Now you need to specify a date range and mag range.

Otherwise you're saying a quake of any size anywhere
in California at any date/time.

Roger

Responses:
[21343] [21344] [21345] [21346] [21347] [21348] [21351] [21352] [21353] [21349] [21354] [21350]

21343

Date: April 06, 2020 at 19:37:12
From: Roger Hunter, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

Excuse me; those details are in the title to your
post.

My bad.

Roger

Responses:
[21344] [21345] [21346] [21347] [21348] [21351] [21352] [21353] [21349] [21354] [21350]

21344

Date: April 06, 2020 at 21:35:29
From: Mikhail, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

Time and magnitude ranges also were in body of my
original post. But picky is good. I like. I should,
then, correct that odds of success are about three
times longer than I stated (after ignoring aftershocks
and events outboard of Cascadia), more as 1 in 850.
(Betting the farm is not advised.)

Responses:
[21345] [21346] [21347] [21348] [21351] [21352] [21353] [21349] [21354] [21350]

21345

Date: April 07, 2020 at 11:52:51
From: Roger Hunter, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

Mikhail;

Now how are you computing probability?

It should be the number of times a window of that
duration contained a quake of that size divided by the
number of windows of that duration thruout history.

Roger

Responses:
[21346] [21347] [21348] [21351] [21352] [21353] [21349] [21354] [21350]

21346

Date: April 07, 2020 at 11:55:19
From: Roger Hunter, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

Should have said a window of that duration contained a
quake of that size in that location....

Roger

Responses:
[21347] [21348] [21351] [21352] [21353] [21349] [21354] [21350]

21347

Date: April 08, 2020 at 10:16:34
From: Mikhail, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

Using USGS “Search Earthquake Catalog” feature, I
custom-searched:

AREA: bounded by 42 & 36 lat, -119 & -126 long, for

MAG: from 6.2 to 6.6 (inclusive), from

TIME: since 1920 (past century)

I ignored all events outside the strict area defined
in my earlier post.

I ignored all events within the strict area that I
judged to be aftershocks (i.e., counted only
“mainshocks”); defining aftershocks for simplicity
as events within one year after a larger quake in
the same general area.

This showed 7 mainshocks satisfying the above
criteria.

365 days/year = 36,500 days/century

7 events/36,500 days = 0.00019 events/day

(0.00019 events/day) x 6 days = 0.0012 events per
6-day period on average, or

1 event per ~870 6-day periods.

Chance odds of success: 1 : 870 (more or less).
QED.

Had I wanted to hedge, I would have stated “MAG 6.2
or greater”.

This would have added 3 more qualifying events
(including Loma Prieta), and raised the chance odds
to 1 : ~600 (but still long).

Responses:
[21348] [21351] [21352] [21353] [21349] [21354] [21350]

21348

Date: April 08, 2020 at 10:51:19
From: Roger Hunter, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

WRONG.

Probability does not include number of quakes.

It is historically, how many times the location was
hit divided by the number of time it could have been
hit.

It's all time windows. If the window is 6 days,
divide the days in the history by 6. Then count how
many of the windows were hit. Divide hit count by
total count. That's probability.

Roger

Responses:
[21351] [21352] [21353] [21349] [21354] [21350]

21351

Date: April 08, 2020 at 16:28:02
From: Mikhail, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

Dear Dr., where have I so blundered as to merit all
caps?

If the window is 6 days, divide
the days in the history by 6.
Window = 6 days
Days in the history = 36,500 days
Number of windows (“total count”) = 36,500 /
6 = 6,083 windows

Then count how many of the
windows were hit.
Windows hit (“hit count”) = 7 (i.e., the
qualifying events in my search)

Divide hit count by total count.
That’s probability.
Probability = 7 (hit count) / 6,083 (total
count) = 0.00115075 (I rounded to 0.0012,
apologies if you deemed that a significant error)

Odds = probability event will occur / probability
the event will not occur
Probability the event will occur = 0. 00115075
Probability the event will not occur = (1 - 0.
00115075) = 0.99884925

Odds of success = 0. 00115075 / 0.99884925,
or, as a ratio, 1 to 868 (in preceding post I
simplified to "1 in 870", apologies again for
my simple significant digits)

It's all time windows
...except for the actual events counted.

Responses:
[21352] [21353]

21352

Date: April 08, 2020 at 20:36:20
From: Roger Hunter, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

Mikhail;

BINGO!

You got it!

Roger

Responses:
[21353]

21353

Date: April 08, 2020 at 21:30:41
From: Mikhail, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

Um, yeah. And I got it right in my earlier posts,
too:

Probability (rough):
http://earthboppin.net/talkshop/rollem/messages/2133
8.html [paste link together] --
"<0.5%"

Probability (precise):
http://earthboppin.net/talkshop/rollem/messages/2134
7.html [paste link together] --
"0.0012 events per 6-day period"

Odds of success (precise):
http://earthboppin.net/talkshop/rollem/messages/2134
4.html [paste link together] --
"1 in 870"

As did you:
"Excuse me.... My bad. Roger"
;-)

Responses:
None

21349

Date: April 08, 2020 at 11:21:30
From: ryan, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

nice bedside manner rog...lol...

Responses:
[21354] [21350]

21354

Date: April 08, 2020 at 23:13:31
From: Eve, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

Cornfucius

Responses:
None

21350

Date: April 08, 2020 at 11:54:16
From: Roger Hunter, [DNS_Address]
Subject: Re: NorCal M6.4 +/- 0.2 on 4/14 +/- 3d PDT

ryan;

could be worse.

roger

Responses:
None

[ Roll & Rock ] [ Main Menu ]

Generated by: TalkRec 1.17
Last Updated: 30-Aug-2013 14:32:46, 80837 Bytes
Author: Brian Steele