1 00:00:00,520 --> 00:00:03,800 Speaker 1: Welcome to Brainstuff from house stuff Works dot com where 2 00:00:03,840 --> 00:00:14,960 Speaker 1: smart happens. Hi. I'm Marshall Brain with today's question, and 3 00:00:15,000 --> 00:00:17,319 Speaker 1: i also have a funny little story that I'm going 4 00:00:17,400 --> 00:00:19,799 Speaker 1: to stick at the end of this podcast and ask 5 00:00:19,880 --> 00:00:22,560 Speaker 1: you a question about it. So here's the question. Is 6 00:00:22,600 --> 00:00:26,560 Speaker 1: it true that scientists are predicting a really big earthquake 7 00:00:26,680 --> 00:00:31,160 Speaker 1: that will sink western California. This often comes up when 8 00:00:31,160 --> 00:00:34,479 Speaker 1: people talk about earthquake activity along the Pacific coast of 9 00:00:34,520 --> 00:00:38,919 Speaker 1: the United States. Seismologists have predicted that a massive scale 10 00:00:39,400 --> 00:00:42,800 Speaker 1: eight point oh or higher on the Richter scale earthquake 11 00:00:42,920 --> 00:00:46,120 Speaker 1: will shake that region sometime within the next thirty years 12 00:00:46,240 --> 00:00:49,279 Speaker 1: or so. This is the so called Big One that 13 00:00:49,360 --> 00:00:54,720 Speaker 1: makes many California residents understandably nervous and inspires a variety 14 00:00:54,800 --> 00:00:59,400 Speaker 1: of apocalyptic disaster speculations. But while the Big One would 15 00:00:59,440 --> 00:01:03,560 Speaker 1: definitely reek mass destruction, it would not sink part of 16 00:01:03,600 --> 00:01:06,520 Speaker 1: California into the ocean, nor would it break the state 17 00:01:06,600 --> 00:01:09,039 Speaker 1: off from the rest of the country or anything like that. 18 00:01:09,560 --> 00:01:13,240 Speaker 1: The idea comes from a misunderstanding of the seismic forces 19 00:01:13,319 --> 00:01:17,080 Speaker 1: that cause earthquakes in the region. To begin with, powerful 20 00:01:17,120 --> 00:01:20,399 Speaker 1: earthquakes occur frequently along the West coast of the United 21 00:01:20,440 --> 00:01:24,280 Speaker 1: States because the region is near a boundary between two 22 00:01:24,319 --> 00:01:28,560 Speaker 1: tectonic plates. If you've read How Earthquakes Work on How 23 00:01:28,600 --> 00:01:31,640 Speaker 1: Stuff Works, then you know that the Earth's surface is 24 00:01:31,680 --> 00:01:35,480 Speaker 1: made up of large, rigid plates that slowly drift over 25 00:01:35,520 --> 00:01:39,440 Speaker 1: the mantle layer below them. At the boundaries between these plates, 26 00:01:39,440 --> 00:01:42,880 Speaker 1: a number of things can happen. The Pacific Plate and 27 00:01:42,920 --> 00:01:47,160 Speaker 1: the North American plates simply grind against each other, one 28 00:01:47,360 --> 00:01:52,880 Speaker 1: creep slowly northwest and one creeps southeast. This boundary forms 29 00:01:52,920 --> 00:01:55,880 Speaker 1: a fault line that extends under the ocean and on 30 00:01:56,080 --> 00:01:59,080 Speaker 1: land along the West coast of the United States. The 31 00:01:59,120 --> 00:02:02,840 Speaker 1: San Andreas Fault in California is the piece that's on land. 32 00:02:03,320 --> 00:02:06,560 Speaker 1: Smaller faults form in the crush material near the boundary 33 00:02:06,600 --> 00:02:09,200 Speaker 1: line due to the forces of the plates pushing on 34 00:02:09,280 --> 00:02:13,440 Speaker 1: each other. Friction builds up along the fault because the 35 00:02:13,600 --> 00:02:17,640 Speaker 1: two sides are pushed very tightly together. If the force 36 00:02:17,720 --> 00:02:21,360 Speaker 1: of friction exceeds the forces moving the earth, then the 37 00:02:21,400 --> 00:02:25,400 Speaker 1: two sides will become locked, so they stop creeping. When 38 00:02:25,440 --> 00:02:29,320 Speaker 1: this happens, tension builds up along the fault line until 39 00:02:29,320 --> 00:02:32,320 Speaker 1: the force of movement is great enough to overcome that 40 00:02:32,400 --> 00:02:35,560 Speaker 1: force of friction and to break the lock. Then the 41 00:02:35,600 --> 00:02:39,919 Speaker 1: pieces of Earth suddenly snap into place, releasing a huge 42 00:02:39,919 --> 00:02:43,560 Speaker 1: amount of energy that causes big earthquakes in the Earth's crust. 43 00:02:44,320 --> 00:02:47,800 Speaker 1: Many scientists estimate that there is enough tension built up 44 00:02:47,840 --> 00:02:52,360 Speaker 1: along some locked California faults that when they do finally slip, 45 00:02:52,680 --> 00:02:57,600 Speaker 1: the earthquake will be extremely powerful. The Hayward fault particularly 46 00:02:57,639 --> 00:03:01,760 Speaker 1: concerns these scientists because it runs are heavily populated areas 47 00:03:01,800 --> 00:03:05,280 Speaker 1: in and around Los Angeles. The notion that part of 48 00:03:05,320 --> 00:03:09,960 Speaker 1: California will break off, though, was likely inspired by the 49 00:03:10,000 --> 00:03:13,840 Speaker 1: San Andreas fault. After all, since the fault goes right 50 00:03:13,880 --> 00:03:16,920 Speaker 1: through California, one part of the state is on the 51 00:03:16,919 --> 00:03:20,320 Speaker 1: Pacific Plate and one is on the North American Plate. 52 00:03:20,720 --> 00:03:23,600 Speaker 1: If those plates are moving in different directions, it makes 53 00:03:23,639 --> 00:03:26,240 Speaker 1: sense that the two pieces of California will move in 54 00:03:26,280 --> 00:03:30,560 Speaker 1: different directions too, and this is indeed the case. But 55 00:03:30,760 --> 00:03:34,400 Speaker 1: even in a massive shift along the fault, the plates 56 00:03:34,480 --> 00:03:38,080 Speaker 1: travel an incredibly short distance. It's a matter of ten 57 00:03:38,200 --> 00:03:42,119 Speaker 1: or twenty feet at most, and even the most extreme shifts, 58 00:03:42,600 --> 00:03:45,600 Speaker 1: the tension can't build up to the point that one 59 00:03:45,840 --> 00:03:49,480 Speaker 1: entire massive land will shift many miles in relation to 60 00:03:49,520 --> 00:03:53,040 Speaker 1: another one, so you will not see any sizeable piece 61 00:03:53,040 --> 00:03:56,920 Speaker 1: of land breaking away from any other. Instead, the pieces 62 00:03:56,920 --> 00:04:00,000 Speaker 1: of land will move away from each other slowly, very 63 00:04:00,040 --> 00:04:04,200 Speaker 1: very slowly, taking millions of years to make large scale changes. 64 00:04:04,480 --> 00:04:07,760 Speaker 1: One end of California may slowly drift so that it 65 00:04:07,880 --> 00:04:11,760 Speaker 1: eventually is underwater after millions of years, but this can 66 00:04:11,840 --> 00:04:16,400 Speaker 1: hardly be construed as sinking into the ocean. Pieces of 67 00:04:16,520 --> 00:04:20,120 Speaker 1: land don't just fall into the ocean, because that's not 68 00:04:20,200 --> 00:04:24,040 Speaker 1: how tectonic plates work. So let me shift gears here 69 00:04:24,040 --> 00:04:26,840 Speaker 1: and tell you a funny story. As many of you know, 70 00:04:27,520 --> 00:04:30,520 Speaker 1: I have been on a diet for about fourteen weeks 71 00:04:30,560 --> 00:04:33,920 Speaker 1: now and I've lost thirty seven pounds. So I got 72 00:04:33,960 --> 00:04:38,280 Speaker 1: this comment on one of my dieting blog posts from 73 00:04:38,320 --> 00:04:42,400 Speaker 1: a reader named Christine, and here's what she says. You're 74 00:04:42,400 --> 00:04:45,440 Speaker 1: doing a phenomenal job. I hope that you will continue 75 00:04:45,440 --> 00:04:48,760 Speaker 1: with updating us each week because reading your posts keep 76 00:04:48,800 --> 00:04:52,680 Speaker 1: my momentum going. Also, I listened to your podcasts and 77 00:04:52,720 --> 00:04:56,480 Speaker 1: I wanted to mention that you sound thinner. Sound is 78 00:04:56,520 --> 00:05:00,200 Speaker 1: in all caps. You don't sound throaty, almost as if 79 00:05:00,200 --> 00:05:05,000 Speaker 1: you've lost weight around your neck, so that is odd. 80 00:05:05,520 --> 00:05:08,080 Speaker 1: If you've ever read my blog posts about this diet 81 00:05:08,120 --> 00:05:10,600 Speaker 1: I've been on, it's called the Ducan Diet, and it's 82 00:05:10,600 --> 00:05:13,440 Speaker 1: worked pretty well to lose thirty seven pounds in roughly 83 00:05:13,600 --> 00:05:18,120 Speaker 1: three months. But I never would have expected or predicted 84 00:05:18,240 --> 00:05:21,560 Speaker 1: or calculated that it would have any effect on my voice. 85 00:05:21,960 --> 00:05:24,440 Speaker 1: So here's a question I'd like to ask. Do you 86 00:05:24,600 --> 00:05:28,960 Speaker 1: think my voice sounds different than say, three months ago. 87 00:05:29,040 --> 00:05:32,000 Speaker 1: If you listen to the podcast regularly, you know you've 88 00:05:32,000 --> 00:05:34,760 Speaker 1: probably heard my voice over a couple of months period. 89 00:05:35,200 --> 00:05:38,320 Speaker 1: Does it sound any different to you? And if it does, 90 00:05:38,520 --> 00:05:41,720 Speaker 1: would you mind leaving a comment? There's Facebook dot com 91 00:05:41,800 --> 00:05:44,159 Speaker 1: slash brain stuff. You could go there and just drop 92 00:05:44,160 --> 00:05:46,680 Speaker 1: a comment on the page. I just be curious to 93 00:05:46,720 --> 00:05:49,920 Speaker 1: know if this is something that is audible to people, 94 00:05:50,240 --> 00:05:53,120 Speaker 1: or if not, or if you don't use Facebook, then 95 00:05:53,240 --> 00:05:56,680 Speaker 1: email me at m brain at how stuff works dot com. 96 00:05:56,760 --> 00:06:00,839 Speaker 1: So it's Facebook dot com, slash brain stuff or m 97 00:06:00,960 --> 00:06:03,440 Speaker 1: brain at how stuff works dot com. I just be 98 00:06:03,560 --> 00:06:09,360 Speaker 1: curious if you can hear any difference. Thanks for more 99 00:06:09,400 --> 00:06:11,920 Speaker 1: on this and thousands of other topics, visit how stuff 100 00:06:11,960 --> 00:06:14,080 Speaker 1: works dot com and don't forget to check out the 101 00:06:14,080 --> 00:06:16,120 Speaker 1: brain Stuff blog on the how stuff Works dot Com 102 00:06:16,160 --> 00:06:19,000 Speaker 1: home page. You can also follow brain Stuff on Facebook 103 00:06:19,080 --> 00:06:21,440 Speaker 1: or Twitter at brain Stuff H. S W.