On Aug 17, 4:16 pm, Weatherlawyer wrote:
On Aug 17, 3:34 pm, rick++ wrote:

Searching the NEIC online catalog returns 34 M8+s in the past 35 years.
There was one year with four (2000) and three others with three and
nine years with none.

I go by a loose "Law of Three" in characterizing earthquake size-frequency;
That is given a mean recurrence interval of "N" years, its not uncommon
to see gaps of 1/3 N to 3N.

I've seen this in San Andreas paleoseismics too.

I suspect this has something to do with the quasi-fractal nature of
seismicity statistics in time, space, and size.
But I'm not sure how to prove this.

Link them to severe weather events for a start. For instance, from a
link supplied in another thread he

I'd thought once I gotr the paragraphs sorted out the rest would be a
pice of cake. But unfortunately the 1920's were still the dark ages of
geo-science.

Hopefully with Weatherlawyer and a few of the other nogoodnicks, there
is a renaissance in progress.

Here is what I have so far, whilst there is still a modicum of
interest:

This is when the fat lady sang:

1927 05 22 - Tsinghai, China - M 7.9 Fatalities 200,000

"The flooding was a result of persistent heavy rains that fell across
the central U.S. starting in August 1926 and continuing through the
spring of 1927.

August to December 1926

Around the middle of August 1926, the rains began to fall over the
upper midwestern U.S. The first storm system lasted for many days,
starting in South Dakota, Nebraska, Kansas, and Oklahoma and moving
eastward into Iowa, Missouri, Illinois, Indiana, Kentucky, and Ohio.

This system was followed within two days by a second and third storm,
which moved across the Mississippi Valley, causing rain to pour for
two weeks.

By September 1, 1926, dozens of streams and rivers began to overflow
their banks and inundate towns from "Carroll, Iowa to Peoria,
Illinois, 350 miles apart". The deluge continued through September
into early October and caused the Mississippi River to rise rapidly,
washing out bridges and railroads. For example, 15 inches of rain fell
over the course of three days in Iowa, flooding Sioux City.

By the end of October 1926, when the rains stopped, flooding was
observed across all of the upper mid-western states, with the Neosho
River in Kansas and the Illinois River in Illinois causing the worst
known flooding in U.S. recorded history."

Anyone might be forgiven for thinking this was the end of the
affair....

It was merely the end of the beginning:

"In mid-December 1926, the storms began anew across the Mississippi
Valley, with snow falling across the north and rain to the south and
east. To the north, Helena, Montana was hit with close to 30 inches of
snow.

To the south in Little Rock, Arkansas, close to 6 inches of rain fell
in one day. By Christmas, thousands were left homeless due to the
flooding and railroad traffic was suspended across the Mississippi
River.

Many rivers rose to their highest levels ever recorded and the gauge
readings across the Ohio, Missouri, and Mississippi rivers from
October to December 1926 were at the highest ever known.

For example, the gauge at Vicksburg, Mississippi along the Mississippi
River in October 1926, which usually was around zero at that time of
year, was over 40 feet (12 meters). This gauge reading foreshadowed
the events to come, as high waters in the spring were expected to
follow.

In early January, no storms brewed over the region, but beginning in
mid-January, the rains began to fall again.

[I've left these spaces blank for when I get my Opera tabs sorted the
way I had them. This essay is turning into a right pain.]

The Ohio River flooded Cincinnati on January 28, 1927. In early
February, the White and Little Red rivers flooded over 100,000 acres
in Arkansas. Rains continued through the end of the month.

[]

In early March, a blanket of snow fell from the Rockies to the Ozarks
in the north and rain deluged areas to the south in the lower
Mississippi Valley. For example, in Mississippi, four inches (10
centimeters) of rain fell on March 16.

Then, from March 17 to March 20, three tornadoes touched down in the
lower Mississippi Valley, killing 45 people and damaging the levees
protecting the surrounding region.

By the end of March 1926, every levee board south of Cairo was
operating 24 hours a day, patrolling the levees for breaches and
sandbagging the levees to prevent overtopping.

[1927 03 07 - Tango, Japan - M 7.6 Fatalities 3,020]

[I have the idea that this was a change in the spells instilled by a
super-typhoon. Unfortunately the chances of finding good records of
them in those days are not very promissing.

It wasn't until satellite data that almost total coverage could be
assumed.

There is a tendency toward long black clouds stretching from hill to
hill in waves covering large tracts of Britain, producing thunder and
hail with this sort of weather in the USA.]

The month of April brought no respite from the rain, and the rivers of
the upper and lower Mississippi Valley continued to rise.

By the second week of April, over 1 million acres of land were
underwater and more than 50,000 people were driven from their homes
and living in temporary shelters in Arkansas, Illinois, Kentucky,
Mississippi, Missouri, Oklahoma, and Tennessee.

The upper and lower Mississippi River - from Iowa to Louisiana - was
in flood stage.

[]

On April 13, tornadoes once again touched down in the region. But the
worst was yet to come for Louisiana. On April 15 (Good Friday), New
Orleans received 15 inches (38 centimeters) of rain over the course of
18 hours, totaling over one-quarter of the city's annual average.

Farther north, Greenville, Mississippi received over 8 inches (20
centimeters) of rain; between 6 and 15 inches (15 and 38 centimeters)
fell in other counties along the Mississippi River.

On the same day, the New York Times reported that "From Cairo to the
sea, the most menacing flood in years was sweeping down the
Mississippi River and its tributaries tonight."

A follow-up article showed pictures of downtown New Orleans with 4
feet (1.2 meters) of standing water, mistakenly stating that the
flooding was due to Mississippi River overflow rather than heavy
rainfall.

Some of the political leaders of the Delta states raised serious
doubts about the levees holding back the waters of the river.

Then, on April 16, approximately 1,200 feet (366 meters) of levee at
Dorena, Missouri, which lay only 30 miles (48 kilometers) south of
Cairo, Illinois, collapsed.

[]

This breach flooded 175,000 acres of land. The volume of water flowing
down the Mississippi River was unprecedented; in 1927, the Mississippi
River south of Cairo carried a volume of water measuring at least 1.7
million (possibly 2 million) cubic feet per second.

In 1844, the record flow of the river near St. Louis was 1.3 million
cusecs; in 1993, the volume was 1.03 million cusecs.

It was inevitable that another breach would happen, but there was
uncertainty as to where it would occur. As a result, thousands of men
struggled to reinforce the levee along the lower Mississippi River
with sandbags.

Then, on Thursday, April 21 at 8:00 am, the levee broke at Mounds
Landing, which lay below the junction with the Arkansas River and
approximately 12 miles (19 kilometers) north of Greenville,
Mississippi. Greenville was flooded the next day.

The breach measured over 3,960 feet (1,207 meters) wide and 100 feet
(30 meters) deep, flooding the Mississippi Delta with a volume of
water measuring 468,000 cusecs.

[]

In only ten days, 1 million acres of land across the delta were
immersed under water at least 10 feet (3 meters) deep. In 2007, a deep
still lake remains at the point where the former levee was breached,
eroding the underlying delta sediments.

More breaches along the levee occurred farther to the south through
the months of April and May, as the floodwater was channeled back once
again through the levees and into the Mississippi River at Vicksburg,
Mississippi.

[]

On May 24, the final breach of the 1927 flood occurred at McCrea,
Louisiana on the east bank of the Atchafalaya levee.

Not actually all that much happening according to this site:

http://earthquake.usgs.gov/regional/...historical.php

1927 05 22 - Tsinghai, China - M 7.9 Fatalities 200,000
1927 03 07 - Tango, Japan - M 7.6 Fatalities 3,020
1926 06 29 - Santa Barbara, California - M 5.5 Fatalities 1

And the conclusion to draw from that is of course the obvious. When
Laki (and then Tambora some 50 years later) erupted spectacularly
there followed a lot of miserable weather.

So it is reasonable to suppose that there must have been an eruption
of some sort that failed to kill enough people for anyone to notice
it.

Typically there was nothing between Katmai and Mt St Helens (then we
had all 4 coming at once) I couldn't find any such an account at any
rate.

Santorini was going strong in that period: http://www.santonet.gr/volcano/islets.html
And there was a major event of some sort at Dallol.

Goodness knows what. Google doesn't.

Nor do meteorological sea level charts exist for the time period so
that a glimpse of the state of the NAO can be had. None that I can
find anyway.

At least not without me going to Exeter.
*******s!

That's a day's drive, two night's digs and another day back. No wonder
the Scots want to feck off. I'd have had enough of it if I were them.