island cassie

We have been having our usual crop of small earthquakes (3.5 ish) which are not worth mentioning, but what is interesting is the movement shown where the roads cross the fault lines. Lately one plate has moved up about 4ft, and another well to the right - the handy road markings illustrate this quite well.

Dalmatiansoap

We had few earthquakes last week but luckly no movments at all.

__________________
https://abnb.me/AXJty518xib

lorax

Neat! Whenever we have temblors up to 5.0 here we just shake for a while, we don't get actual faultline movement. The last time I saw something like that was after a 6.7 centered in Morona-Santiago, which is about 250 km to the South of me. In Quito, we got road faults from that one in the historic center - the cobbles all just shifted about a foot and a half to the left in the Plaza Grande, and all the fruit came off the palms.

island cassie

They are interesting to keep an eye on - just as long as they keep slipping! When they stop - look out, a biggie might be on it's way.

lorax

I'm curious - what would you define as a "big" earthquake?

Here, we say anything over 5.0 because that's the point at which things start to get damaged (plates fall, glass breaks, and very old adobe construction may fall over). Above 5.5 is considered severe, and 6.0 and above, no matter where it happens, is felt all through the country to varying degrees and normally those are the ones that cause the biggest damage. We get a 6+ about once every two or three years, mostly epicentered in the Amazon so there's not a whole lot of problem in the cities.

momoese

Wow, that's some movement! We have a place here in So Cal where there is an ongoing landslide going out to sea called Portuguese Bend in Palos Verdes. They are constantly repairing the road.

The moving road.

The Palos Verdes peninsula has an interesting history geologically speaking, not to mention all the politics and lawsuits over the years, and some people still want to develop the area! I remember seeing one of the houses that was affected by the movement back in 1978. It was a single level home that turned into a multi level!
Portuguese Bend - Wikipedia, the free encyclopedia

island cassie

I guess anything over about 6 that causes loss of life and damage to buildings. In general buildings are constructed with earthquakes in mind We had a 6.4 in 2003 that killed a few people, but after sitting outside all night through the aftershocks, we really had to go looking to find signs of damage.

Mostly ours are between 3 and 4, and either on the faults in the photos or else in the Mona Channel between us and Puerto Rico.

island cassie

Interesting Mitchell! Our roads regularly slide down the mountains too - the last time we attempted one particular road, we counted 13 landslides - haven't been that way for a while now! I think I have a picture somewhere.

lorax

Landslides are a major issue here, too. Not so much on the coast as in the Sierra, especially the West slope roads that are the main transport routes from the coast. One stretch of road by Santo Domingo falls off the mountain twice a year, like clockwork. It's not a tectonic issue though, it has to do with the rainy cycles and unstable hill geology.

island cassie

Yep - we are much the same - torrential rain and unstable land coupled with very steep mountains are bad news around here. But they are starting to repair the slips in a better way now by paying attention to the drainage and using gabions. Some places however are always on the move.

lorax

There's one stretch of road here where they cut tunnels through the bedrock rather than try to repair it anymore - it's a fantastic way to go now. However, even with gabions and culverts and careful attention to drainage, there are still roads that come down every time it rains. I got trapped by landslides on the highway once between the jungle and the hot springs, and the bus just looked for a place where landslides wouldn't hit it and we parked for 3 hours waiting to see if there were roads to go on, or if we had to turn back. Adventures! I almost prefer earthquakes, myself.