The St-Lawrence rift system and other east coast fault

Edit : Sorry , i'm new to this forum , can an admin repost it in (fragile Earth ) section please


So i finish , i think i got almost all the information for this part of the world , so i compiled it ^^ , here is my *article*

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For fun , i will put all my info about earthquake on the east coast here , instead of putting it in 10000 topics

This will be complicated to explain , but i will try , don't be mad if my english isn't my best language

One thing that make fear on my mind is the St-Laurence Paleorift . It's start on the northwest side of Greenland , take a turn into the St-Laurence gulf , follow it and slit into 2 majors faults systems

One stay a rift system, that start 50 mile north of Ottawa , take a bath under the great lake , pass Niagara fall and buffalo and connect to an well know fault named the New Madrid .

The other is a serie of supracrustal fault , spliting 100 mile east of Montreal , follow the Richelieu river to the appalachian range , Take a bath to the Atlantic ocean close to Charleston and strike Porto Rico . And collision upper movement fault name The Logan Fault line follow the same
way. This faultd is responsible of the Newest upper movement of the Appalachian range , that strangely , look younger that they should be , i will show you all the faults lines latter on the topic .

Here is the map of the east coast fault line
hpics.li...

Here is a cut of the underground of montreal , you can see the rift fault and the Logan fault , the logan fault is the one that cut the rift fault at the right of the image .

hpics.li...

and here is where the cut is :
hpics.li...

More we get to the north , more the rift is old , Greenland get off from america at the same moment the Himalaya was created

Here is a cut from the underground of Quebec , close to the City of Les Eboulements (remind of the great 1663 Quake)
hpics.li...
And here is where the cut is :
hpics.li...


Other informations , if the rift have to go off (collapse event or not ) The energies will be transmitted from 2 side , the East and the West .

So , the New Madrid and The east coast fault system will get massive stress

here is historical info for all the region on the east coast
Here is Info on the 7.2 grand banks earthquake in 1929

earthquakescanada.nrcan.gc.ca...

And the 7.0 Charlevoix Earthquake in 1663.

earthquakescanada.nrcan.gc.ca...

The 1933 Baffin Bay earthquake

earthquakescanada.nrcan.gc.ca...

1884 east coast Shake

www.gendisasters.com...

East coast quake History and hasard by state :

New York:
earthquake.usgs.gov...

earthquake.usgs.gov...

South Carolina:
earthquake.usgs.gov...

earthquake.usgs.gov...

Vermont :
earthquake.usgs.gov...

earthquake.usgs.gov...

Maine:

earthquake.usgs.gov...

earthquake.usgs.gov...

Virginia:

earthquake.usgs.gov...

earthquake.usgs.gov...

Maryland:

earthquake.usgs.gov...

earthquake.usgs.gov...

North Carolina:

earthquake.usgs.gov...

earthquake.usgs.gov...

District of Columbia:

earthquake.usgs.gov...

earthquake.usgs.gov...

New jersey:

earthquake.usgs.gov...

earthquake.usgs.gov...

Massachusetts:

earthquake.usgs.gov...

earthquake.usgs.gov...



So , it's happened before .

Here is The USGS Earthquake Hasard map

earthquake.usgs.gov...


And now , Some study are made , but very contradictory that said 15% chance of 7.0+ earthquake in Montreal in the next 50 years (Some said it's 5% chance , other said it's imminent .
www.canada.com...

do you think it's the fault of the easter side of the craton , but the craton is not the problem for this area

The craton finish in this st-Lawrence because of the St-lawrence rift , check this area , some 7.0 earthquakes happened in the past , and one possible 8.0 and bigger .

Montréal - Quebec - Ottawa are in the top 5 cities that risk an earthquake in canada , 1 one is Vancouver . So check this area . It's had a possible connection to the New madrid and the Logan fault

the rist is expanding , but is block by the craton on side , and the midatlantic ridge the other side , so pressure is building up on the east side of the craton and the appalachian mountain (virginia earthquake ... ^^ )


I think you will have some reading , i found load of information about this rift , and is connection to the New Madrid by the Lake superior and michigan , new study found that it's not just in Quebec , but in the Whole eastern and midwest side of the North America .
These article and scientist study are some time hard to read and the information on it is very complicated , i hope you know a little bit of geology my friend

here it is :
www.cseg.ca...

www.mendeley.com...

iicph.org...

newsrelease.uwaterloo.ca...

gretchen.geo.rpi.edu...

Just for fun : en.wikipedia.org...:Rift_valleys

gizmo.geotop.uqam.ca...

in french : the great 1663 earthquake
www.republiquelibre.org...

rruff.geo.arizona.edu...

www.scribd.com...

books.google.ca... fr&ei=YM2uToJXodfRAdSr2KUP&sa=X&oi=book_result&ct=result&resnum=2&ved=0CCcQ6AEwATgU#v=onepage&q=st-lawrence%20fault%20system&f=false

And i don't finish now

If somone very very evil want to create a megaquake in America , you will say , crush the new madrid ?

Why not attaking the center and the east coast of america and canada in the same time ?

how to do this ? Trigger earthquakes in the St-Lawrence rift system , the Logan Fault line , greenburg fault line , New york fault line , virginia earthquake zone , New madrid earthquake zone Taconic mountain supra crustal fault , east coast boundry fault , montmorency earthquake zone Richelieu river Rift , Cap Tourment fault ... that some of the fault , not all

The 3 big one , that can do m7.5+ are The St-Lawrence rift , The New madrid and the Logan fault

Check this out :

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Quebec region :

The Quebec portion of the St-Lawrence rift

Virginia faults lines

New York Ramapo fault system

East coast and missisipi fault system

Grenville fault system

New york state fault system (transition of the St-Lawrence rift to the Ramapo fault system

DC-Baltimore Blue ridge fault system (connection to the Ramapo fault system and Grenville fault system )

Ottawa Bonnechere Graben (continuation of the St-Lawrence Rift to the great lake

Lake Superior Keweenaw anomaly (continuation of the Bonnechere Graben into lake superior

Niagara Escarpement anomaly (unnamed faults lines )

Then , you had Wisconsin , but no fault line map where found , and not a lot of research are made to name the Fault line , but they exist , wisconsin had earthquake by the pass and this unnamed faults lines connect the Niagar escarpement to the New madrid sismic zone

So if somone want to make an earthquake , he had a lot of choice for the epicenter

Info topic is an info topic

Yeah , after 3 months , all earthquke canada seismometer a up again


MNTQ continue to show strange ground mouvement
earthquakescanada.nrcan.gc.ca...=MNTQ.BHZ

Montreal , race california for the Big one
But this 3 500 000 hab city will just collapse on hitself


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What we don't need now is an earthquake
POSTED BY VICTOR SCHUKOV AT 7H17

Is this a bad time to mention that the island of Montreal floats perilously over a major Laurentian fault line?



Montreal suffers from post-glacial rebound where during the last glacial period - 20,000 years ago - the island was stomped into the ground by kilometres deep ice, and now takes back squished crust in bits we feel as tremors.





Imagine how many touchy sinkholes, how many clinging slabs of overpass and rusted bridge trusses will cave with a serious shrug of touchy mantle just antsy to return to its former position.



In our nape of the woods, we have about 450 teeny shakers a year of which maybe four hit over 4.0 on the Richter scale, sounding like someone knocking on your door at 3 a.m.

Every few decades we have maybe a couple over 5.0, inciting furniture to move across one's living room in a conga line, the minimum level for the advent of damage. But we have had some jolts as high as 6.5 up north. Montreal, by the way, is one of two active epicentres in western Quebec and experts predict that it is a leg race between us and California as to who gets flattened first.

Rest of the Article here : www.westislandgazette.com...


Edit : From Canadian disaster encyclopedia

Earthquakes
Although the Pacific Coast and parts of central and Atlantic Canada have been shaken by earth tremors, the only one (magnitude 7.2) causing extensive loss of life was centered about 250 km south of the Burin Peninsula, Nfld, on 18 November 1929. A 5m TSUNAMI struck Newfoundland's Burin Peninsula, sweeping away houses, boats and fish stages. Damage was estimated at $1 million; 27 people died. The lower mainland and Victoria, BC, probably have Canada's highest risk of a devastating and death-dealing earthquake, and so far in recorded history have been lucky. There is now good evidence that a very strong earthquake occurred on 26 January 1700 and produced a huge tsunami all along the West Coast.

And the last one : Montreal earthquake building code from MGill university.

www.mcgilldaily.com...

We often take for granted the idea that the buildings we use every day will remain standing. This becomes most apparent during seismic events when the structural capacity of the built environment is put to the ultimate test. Yet the damage caused by extreme earthquakes is highly variable, which is in fact best illustrated by the differences in the destruction caused by recent earthquakes in Haiti and Japan ...



An earthquake in Quebec region , can be the biggest disaster recorded on the North america , hospital will be dommaged and ineffective , Montreal and Laval island can be isolated if the bridges collapses (They already had problem )

And we don't know the repercution on the fault system , just hope a collapse event isn't coming

How , by the way

I found an old supervolcano in Quebec (The black river megacaldera complex )
Full geological information here : www.divex.ca...

Wikipedia crushed and fade version here :
en.wikipedia.org...

More i learn about Quebec past geological activity , more i understand the role of the St-lawrence rift in the reactivation of the appalachian and the formation of a subduction complex in the west part of the Atlantic

50 -100km from the United stade and Canada eastern coast line

From the start of North america plate , there was gigantic magmaplume under the East coast , and this is what is reactivating the rift

here's a quake map in real time

quakes.globalincidentmap.com...

Greater LA had a quake 12 mins ago 2.4 magnitude

And Quebec - Ontario

2.4 :18 hours ago

Sadly , earthquake canada don't show all the earthquake , the live seismographer indicate more than 5 shackers a days

Wow, that's a lot of work you put in!
In live in St-Jerome, Quebec myself so I'm luckily in a safe zone if ever anything happens.

reply to post by warstorm9


I'm keeping an eye on the New Madrid fault as in runs through several states including where I live in Ky

The great 1663 earthquake

What is likely the worst earthquake in Northeast history since French and English settlement occurred on February 5, 1663. In Boston, chimneys were knocked down, floors collapsed, and terrified residents sought refuge in the streets. In rural areas, the earth opened up and cut deep crevices. In French Canada, mountains were toppled and an island in the St. Lawrence was uplifted. A pre-shock occurred two weeks earlier of significant magnitude, as well as many damaging after-shocks.
The following article from the August 24, 1786 Cumberland Gazette (Portland, ME) describes the great quake: "On January 26, 1663 [Old Style], 'at the shutting in of the evening,' another measurable earthquake shook New-England. From the general expressions the writers who speak of it use, it seems to have been one of the greatest this country ever felt. It is represented as being preceded with great noise and roar. Mention is made of the houses rocking, the pewter falling from the shelves, the tops of several chimneys falling in, the inhabitants running out into the streets, passengers being unable to keep on their feet, &c. As to its course, duration, or extent, nothing is to be found of the New England writers. But they are well described in the accounts that were given of this earthquake in Canada.
At the same time, February 5, 1663 [New Style], 'about half an hour after five in the evening,' a most terrible earthquake began there. The heavens being very serene, there was suddenly heard a roar, like that of a great fire. Immediately the buildings were shaken with amazing violence. The doors opened and shut of themselves, with a fearful clattering. The bells rang without being touched. The walls split asunder. The floors separated, and fell down. The fields put on the appearance of precipices, and the mountains seemed to be moving out of their places: and amidst the universal crash which took place, most kinds of animals sent forth fearful cries and howlings.
The duration of this earthquake was very uncommon. The first shock continued half an hour before it was over; but it began to abate in about a quarter of an hour after it first began. The same day, about eight o'clock in the evening, there was a second shock, equally violent as the first; and in the space of half an hour, there were two others. The next day about three hours from the morning there was a violent shock, which lasted a long time: and the next night, some counted thirty-two shocks; of which, many more were violent—Nor did these earthquakes cease until the July following.
New-England and New-York were shaken with no less violence than the French country. And, throughout an extent of three hundred leagues from east to west, and more than one hundred and fifty from north to south, the earth, the rivers, the banks of sea, were shaken with the same violence. The shocks sometimes came on suddenly; at other times by degrees. Some seemed to be directed upwards; others were attended with an undulatory motion.—And throughout the vast extent of country to which they reached, they seemed to resemble the motions of an intermitting pulse, with irregular returns; and which commenced through the whole at the same hour.
This earthquake was attended with some remarkable effects. Many fountains and small rivers were dried up. In others, the waters became sulphureous: and in some, the channel in which they ran before, was so altered that it could not be distinguished. Many trees were torn up, and thrown considerable distance. And some mountains appeared to be much broken and moved. Half way between Tadoussac and Quebec, two mountains were shaken down: and the earth thus thrown down, formed a point of land, which extended half a quarter of a league into the river St. Lawrence. The island Aux Coudres, became larger than it was before: and the channel in the river became much altered.
From these accounts it is evident, that Canada was the chief seat of these concussions: and of consequence, as it proceeded from those parts, its course must have been from some point between the west and north; probably much the same with [the earthquake] of 1638."

Edit:
2011/11/29 17:02:25 47.55N 70.25W 14.0 3.4MN Ressenti ZONE SISMIQUE de CHARLEVOIX,QC. Ressenti

Hmm, I live in the Outaouais region (near Ottawa), and I wasn't fully aware that we had fault line around here.
Of course I never really checked for it, earthquakes are sort of rare in our region but they happen. Last one I remember was a mag. 5 (or close to it) on June 23rd 2010. It was quite shaky.
Thanks for your post Warstorm.

reply to post by SolidGoal


Bravo for all your hard work and information! I have to bookmark this thread, because I've always had difficulty finding out info on the fault lines in Canada, and you've put in a ton of things to read. So Montreal can just collapse, you said? Is it the top of an old volcano? Oh, and can you tell me what island jutted upwards into the St-Lawrence?

When i talk about a collapse event , i'm not taking about a physical collapse ,just a chain reaction in the rift , collapsing (20-40cm ) the top of the rift , and move the rift extremity east and west (like all rift or ridge system)

That mean a big shaker 7.0+ mag with load of aftershock .

but when ? nobody now .

It's happened by the past , it's overdue , and Quebec doesn't good for para-seismic building .