Mojave Desert, Pasadena, California discussed on Morning Edition


Five years ago. This ancient fault line help define how people suffered in the great Northridge earthquake as the waves came from the north traveling south into the LA basin. They came up through the soft soils as the wave travels from hard rock and to the softer soils, the amplitude of the waves go there was amplification locally of the shaking right around here. And a lot of vulnerable structures. Flaps say. Also in the program, how the Carribean could supply nearly half the world's fish another threat to corals, and we say farewell to one of masses most successful missions. But I the ground that Los Angeles is built on is. You just heard not only are there are a host of force threatening the area, and it's twenty million population. But how bad the shaking will be when there's enough quake depends on the material beneath your feet or beneath your building's foundations. Fiber optics. Also cross the city and here at Caltech seismologist. John Wayne, John is proposing to use that optical network to do a three D scam of the basin in unprecedented detail, small seismic shaking can disturb the light traveling through a fiber. So that the network acts as a series of ready made seismometers how good that's what John Wayne has been checking on a network far out in the Mojave desert trying about twenty cable in Mojave desert. So we attached to the interrogation unit on why the fiber and turned that twenty criminal non-cable to five thousand sensors five that's basically a four meter four means yet. So you can actually measure just how much. Yes. How much of the K by being stretched or compressed? You're doing this and doing. This Mojave desert. Also interesting, well, the Mojave desert is of particular, quiet place. Okay. So there are far away from Carson heard like CD's with a lot of traffic, noise, industrial noise and also relatively far away from the ocean. So that noise level seismic noise level is really low. So we think of this as the ideal place to benchmark verify the quality of their five seismic data. So if you own positive. I felt the lorries rumbling. Variety. We do have experimented theory in Pasadena, and because of all the traffic noise annoyed are so high you always get a clean and fiber seismic arrays by they're not a tiny you how small singular attack because it's all covered by the strong noise. This particular case we were able to hack the magnitude seven earthquake the four thousand could hinder away from their side. So this was away round the do. How much moving on those four meters. Getting these automatic Ron's on the order of microns. Yeah. Smaller detecting that. In the fiber optic from something that rumbled thousand kilometer away. Proves VAT after the desert. I mean, can you get the kind of information? The tech stocks emojis need to understand. So for example, he this paper which showed that with this twenty Ray, we can start to eat meat how the seek knees earth shallow layers. The outer layer is changing interested in in this area is pretty flat. We'll get almost consistent signals rather. For the future. If we have a larger fiber say across the southern California all across the entire continental US, then we were able to map how you know, the outer layers sicknesses change in space. This is a bit like Notre Sam scaring. Yes. The much finer resolution because in the past the we sound for their sickness at about every ten kilometer past most places out of every seventy one hundred kilometer now, some potentially sound play that every ten meter scale. That's something. Interesting. Physics question. Yeah. I mean, the response interesting. Okay, here you are in a city that's waiting for quake. Yes, it's got to be more technologically. Huge numbers of optics. Yes. Chance or even a need. This kind of fiber optic system. Could replace the. I didn't say replace they complement because their traditional says, mommy hers thus theory of bad her in a sensitivity compared to their fibers as Margie a sensors by the fiber is providing us, they're kind of spatial coverage. You need for example, as you said, Los Angeles, southern California is a seismically active area. We wonder what's gonna be the shake in future earthquakes and from pas earthquake. We know earth shaking can change rapidly from place place within one city, two blocks. You could have very different shaking. That's could be due to the shallow structure being very different. Okay. Those kinds of information would never really have in the past with when you're only how one sensor every ten kilometers. Right. But a will now with fiber you covered in the city with meter the resolution. You can start image. How shallow structure is changing. Predict how the are going to be in a future. You did this experiment. Optima harvey. Because he got away from right? Right, right. If you bring it back into. Well, we'll have been working on that. We have been collecting a couple of months of data in Pasadena. Fisher show, you this because this is actually a fiber cable impassively now we're actually now turning this cable into a seismic already. Let's see LARs. So I I'm not sure we want to give. So you've got so this oughta blue lines here we are here. Whereas here all this. Blue lines are fiber cable, deployed by the CTO Pasadena, quite interesting. Right. So currently we are turning this particular table on fair oaks and to allow small Rose Bowl and the two awareness in avenue as a cable cable ethnic sensor. On the planning as you said to form loop back. I the car tag, the interesting thing is that from what you're saying. You will know the seismic activity every four yes, yes. We're gonna map how the shaking is going to be everywhere in Pasadena allocate, and you don't actually have to install any with. They'll have to go along the street the installed the sensor seize all the data were comeback in light speed to our data center. We don't have the go. They're using theraflu empowers radio to transfer the data back Sean win John of Caltech university where Charles Richter gave us the historic earthquakes scale. Details of his research of just been published by the journal geophysical research, letters, there's a link on the science in action webpage at BBC World, Service dot com and all the reporting on L A's preparations for the next big one in discovery next month. Southern California is home to an incredible constellation of world ranking universities, including two hours up the case from LA UC Santa Barbara, which has a strong line in marine research team that has been looking into the potential for deep sea fish farming to help feed the world and reported just recently that the Caribbean alone could actually meet much of the world demand. I met two of the team Tyler Clavell and Lennon Thomas on a sunny terrace. Overlooking the Pacific. Yeah. We found there was a huge potential for offshore aquaculture production. And I think the really interesting thing was is it's in a very small amount of area when you say huge potential. We're looking at about half the current production of global wild fisheries. Can't be replicated just by doing agriculture. Very simple. Yes. And this is a theoretical study. But I think the overall message is there is a large potential for offshore aquaculture production to pretty super seafood for the region. And as an alternative protein source too wild fisheries, which are overexploited. So what is it? You're looking for areas that have a suitable depth range, which is about twenty two one hundred meters. Areas that have a little bit of current. But current speeds aren't too high. So they're less than on average one meters per second areas with ideal temperatures for Kobe and areas that aren't already designated as protection areas or shipping lanes. Do you know how much water can produce factors in the main factor really is temperature sea surface temperature? So fish are active therms their growth rate is controlled a lot by the temperature of the water. And so there are some pretty good models that can can estimate about how fast a fish might grow. Given a certain temperature range. So what sort of numbers, you talk you that? So right now, the Caribbean region produces about three hundred thousand metric tons of seafood through wild fisheries capture and aquaculture combined and our model. Estimated offshore aquaculture prudential to be able to produce about thirty four.

Coming up next