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| · | The Silverpit Impact Crater Is First Discovered |
| 0:00 | · | Back in 2002, during routine oil and gas |
| 0:03 | · | exploration, two geoccientists from BP |
| 0:06 | · | were combing through seismic data from |
| 0:08 | · | the southern North Sea. Their work was |
| 0:10 | · | supposed to be about identifying |
| 0:11 | · | subsurface structures for hydrocarbon |
| 0:13 | · | exploration, but they noticed something |
| 0:15 | · | odd in the seismic images. There |
| 0:17 | · | appeared to be concentric rings beneath |
| 0:19 | · | the seabed, patterns that didn't fit |
| 0:20 | · | neatly into the normal geological story |
| 0:22 | · | of the region. When they looked closer, |
| 0:25 | · | they thought it resembled something that |
| 0:26 | · | might form from an asteroid impact |
| 0:28 | · | rather than ordinary sedimentary or |
| 0:30 | · | tectonic processes. They published their |
| 0:32 | · | observations in nature in 2002. And with |
| 0:35 | · | that, the silver pit mystery began. |
| · | The Silverpit Mystery |
| 0:37 | · | Several alternative theories were |
| 0:39 | · | floated after 2002, including the idea |
| 0:42 | · | that the site was nothing more than a |
| 0:43 | · | collapsing salt dome rather than an |
| 0:45 | · | asteroid crater. But it wasn't until |
| 0:47 | · | this year that scientists finally got to |
| 0:49 | · | the bottom of the mystery. At last, a |
| 0:51 | · | sight's true origin has been revealed. |
| 0:53 | · | It is without a doubt an impact crater. |
| · | The Silverpit Impact Structure |
| 0:57 | · | The Silver Pit structure lies about 130 |
| 0:59 | · | km east of the Humber Estuary, roughly |
| 1:02 | · | 80 mi off the Yorkshshire coast, buried |
| 1:04 | · | deep beneath the floor of the North Sea. |
| 1:07 | · | At the surface today, the water there is |
| 1:09 | · | shallow by ocean standards, about 40 m |
| 1:11 | · | or so. Beneath that lies hundreds of |
| 1:13 | · | meters of sediment that had built up |
| 1:15 | · | since the impact. When it happened, sea |
| 1:17 | · | levels were different, but the site was |
| 1:19 | · | still underwater. At the time of the |
| 1:21 | · | impact, the asteroid would have smashed |
| 1:23 | · | into a seabed covered by perhaps a few |
| 1:25 | · | hundred meters of water. The geology of |
| 1:27 | · | the region includes upper Cretaceous |
| 1:29 | · | chalk, Jurassic shells, and even deeper |
| 1:31 | · | Peran salt deposits. These layers played |
| 1:34 | · | a role both in how the crater formed and |
| 1:36 | · | how it was later preserved. The crater |
| 1:38 | · | itself is about 3.2 km in diameter at |
| 1:41 | · | its core, but a disturbed zone spreads |
| 1:43 | · | outward as much as 18 to 20 km. At the |
| 1:46 | · | center sits a raised bump, the so-called |
| 1:48 | · | central uplift dome, which is typical of |
| 1:50 | · | larger impact craters that undergo |
| 1:52 | · | collapse and rebound after the initial |
| 1:54 | · | explosion. Around the central peak are |
| 1:56 | · | concentric rings and faults. Structural |
| 1:59 | · | features that ripple outward and show up |
| 2:00 | · | clearly in seismic images. Taken |
| 2:03 | · | together, the shape and the geometry |
| 2:05 | · | strongly resemble other confirmed impact |
| 2:06 | · | craters around the world. As mentioned |
| · | The Geological Debate |
| 2:09 | · | before, from the moment it was first |
| 2:10 | · | described, geologists argued over |
| 2:12 | · | whether Silver Pit really was an impact |
| 2:14 | · | crater. An alternative explanation was |
| 2:16 | · | salt tectonics. Beneath the area lie |
| 2:18 | · | thick layers of perian zextine salt |
| 2:20 | · | which are known to move and deform under |
| 2:22 | · | pressure. As salt migrates or dissolves, |
| 2:25 | · | overlying sediments can collapse, |
| 2:26 | · | creating circular features that |
| 2:28 | · | sometimes mimic impact structures. Many |
| 2:31 | · | geologists in the years after 2002 |
| 2:33 | · | believe Silver Pit might be one of |
| 2:35 | · | dozens of such saltreated collapse |
| 2:37 | · | structures in the North Sea. The problem |
| 2:39 | · | for the impact theory was that while the |
| 2:41 | · | structure looked like an impact crater, |
| 2:43 | · | it lacked a classic smoking guns such as |
| 2:45 | · | shocked quartz, melt rocks, or ejector |
| 2:47 | · | deposits. In fact, in 2009, a formal |
| 2:50 | · | debate at the Geological Society of |
| 2:52 | · | London concluded with most geologists |
| 2:54 | · | leaning toward a non-impact origin. For |
| 2:57 | · | more than a decade, Silipid's true story |
| 2:59 | · | remained unsettled. What changed |
| · | The Recent Data That Led To The Discovery |
| 3:02 | · | recently is that new data have finally |
| 3:03 | · | provided the missing piece. A team |
| 3:06 | · | revisited the site with improved |
| 3:07 | · | three-dimensional seismic imaging and |
| 3:09 | · | also analyzed mineral samples more |
| 3:11 | · | closely. The higher resolution data |
| 3:13 | · | showed the crater bowl, the central |
| 3:15 | · | peak, and a concentric faults in clearer |
| 3:17 | · | detail than ever before. More |
| 3:19 | · | importantly, the team identified |
| 3:21 | · | microscopic mineral grains displaying |
| 3:23 | · | shock defamation, evidence of pressures |
| 3:25 | · | far beyond what normal tectonics can |
| 3:27 | · | achieve. Shock metamorphism is widely |
| 3:30 | · | considered the gold standard for proving |
| 3:31 | · | an impact origin. In addition, fossil |
| 3:34 | · | assemblages in sediments above and below |
| 3:36 | · | the crater allowed scientists to refine |
| 3:38 | · | the timing, showing that the event |
| 3:40 | · | happened around 43 to 46 million years |
| 3:42 | · | ago in the Eene epoch. Numerical models |
| 3:45 | · | of impact dynamics confirm that the size |
| 3:47 | · | and shape of silver pit could indeed be |
| 3:49 | · | produced by an asteroid of about 120 to |
| 3:52 | · | 160 m striking at typical cosmic |
| 3:55 | · | velocities of 20 to 50 km/s. |
| · | What The Asteroid Collision Would've Looked Like |
| 3:58 | · | If you imagine the scene 43 million |
| 4:00 | · | years ago, a rocky asteroid perhaps 150 |
| 4:03 | · | m across plunged into the North Sea |
| 4:05 | · | basin, traveling at tens of kilome/s. It |
| 4:08 | · | had the kinetic energy of hundreds of |
| 4:10 | · | megat tons of TNT. When it hit, the |
| 4:12 | · | water column briefly cushioned a blow, |
| 4:14 | · | but was instantly vaporized along with |
| 4:16 | · | much of the rock beneath. The impact |
| 4:18 | · | gouged out a bowl 3 km wide, blasted |
| 4:21 | · | apart chalk and shale layers, and caused |
| 4:23 | · | the seabed to rebound into a central |
| 4:25 | · | peak. Rock fragments and water were |
| 4:28 | · | thrown skyward while enormous shock |
| 4:29 | · | waves radiated through the basin. In the |
| · | The Mega Tsunami The Collision Generated |
| 4:32 | · | sea above, waves as high as a few |
| 4:34 | · | hundred meters would have formed, |
| 4:35 | · | sending mega tsunamis outward that could |
| 4:37 | · | have battered coastlines around northern |
| 4:39 | · | Europe. For marine life nearby, the |
| 4:41 | · | event would have been devastating. But |
| 4:43 | · | on a global scale, it was not large |
| 4:45 | · | enough to trigger mass extinctions like |
| 4:46 | · | the far bigger chicks loop impact that |
| 4:48 | · | ended the age of the dinosaurs. One of |
| · | Why The Silverpit Crater Has Survived Intact |
| 4:51 | · | the reasons the crater has survived so |
| 4:53 | · | well is that it was quickly buried under |
| 4:54 | · | layers of sediment. Over millions of |
| 4:56 | · | years, additional strata sealed it away |
| 4:58 | · | from erosion and surface weathering, |
| 5:00 | · | preserving its shape like a fossilized |
| 5:02 | · | scar. Being offshore also helped. Impact |
| 5:05 | · | craters on land are often eroded, |
| 5:07 | · | faltered, or buried by subsequent |
| 5:09 | · | volcanism. But under the seabed, the |
| 5:11 | · | structure remained intact until seismic |
| 5:13 | · | surveys for oil and gas exploration |
| 5:15 | · | revealed it. The advances in imaging |
| 5:17 | · | technology combined with new |
| 5:19 | · | stratographic dating methods and |
| 5:20 | · | microscopic mineral analysis finally |
| 5:22 | · | gave geologists the tools they needed to |
| 5:24 | · | settle the argument. What makes the |
| · | The Chance Discovery |
| 5:26 | · | silver pit story even cooler is how it |
| 5:28 | · | all came together by chance. Oil |
| 5:30 | · | companies were just out there scanning |
| 5:32 | · | the seabed looking for the next big gas |
| 5:34 | · | reservoir and they accidentally stumbled |
| 5:36 | · | on one of the best preserved asteroid |
| 5:38 | · | craters in Europe. They went trying to |
| 5:40 | · | rewrite Earth's history but that's |
| 5:42 | · | exactly what happened. Then came the |
| 5:44 | · | geologists who argued back and forth for |
| 5:46 | · | years. Was it salt collapse or was it |
| 5:49 | · | really an impact? In the end, the |
| 5:51 | · | evidence tipped toward the asteroid |
| 5:52 | · | theory and suddenly this quiet patch of |
| 5:54 | · | the North Sea had a dramatic backstory. |
| 5:57 | · | I like to think about it this way. A |
| 5:59 | · | rock the size of a city block comes |
| 6:00 | · | screaming in from space, slams into a |
| 6:02 | · | shallow sea, and leaves a scar that |
| 6:04 | · | survives for over 40 million years |
| 6:06 | · | buried under mud and chalk. We only |
| 6:09 | · | found it because of modern technology |
| 6:10 | · | and a bit of luck. The eene world in |
| · | Life During The Eocene |
| 6:13 | · | which this impact occurred was warm and |
| 6:15 | · | dynamic. Mammals were diversifying. |
| 6:17 | · | Marine ecosystems were rich and Europe |
| 6:19 | · | looked very different. The North Sea |
| 6:21 | · | basin was shallower and more restricted |
| 6:23 | · | than it is today, making the tsunami |
| 6:25 | · | effects potentially severe in local |
| 6:27 | · | regions. Still, it was a contained |
| 6:30 | · | catastrophe, something that shook |
| 6:31 | · | northern Europe, but left little trace |
| 6:33 | · | elsewhere. If anything, Silver Pit |
| 6:35 | · | demonstrates what happens when an |
| 6:37 | · | asteroid of medium size, far smaller |
| 6:39 | · | than a dinosaur killer, but large enough |
| 6:41 | · | to devastate a region, strikes the |
| 6:42 | · | Earth. Even with the new evidence, some |
| · | The Questions That Remain Unanswered Thus Far |
| 6:45 | · | questions remain. Ideally, geologists |
| 6:47 | · | would like to recover more core samples |
| 6:49 | · | from the crater central peak or rim to |
| 6:51 | · | find unambiguous melt rocks. They would |
| 6:53 | · | also like to identify tsunami deposits |
| 6:55 | · | or eject layers in nearby sediments that |
| 6:58 | · | could be tied directly to the event. And |
| 7:00 | · | while the seismic images clearly show |
| 7:02 | · | concentric rings, researchers are still |
| 7:04 | · | debating the precise mechanics of how |
| 7:06 | · | those rings formed. Whether by slumping |
| 7:08 | · | of sediments into the crater or by |
| 7:10 | · | direct fracturing from the impact shock, |
| 7:12 | · | these lingering details are the final |
| 7:14 | · | pieces of the puzzle. |
| 7:16 | · | The silver pit discovery matters for |
| · | Conclusion & Patreon / YouTube Member Thank You! |
| 7:18 | · | more than just local geology. It adds to |
| 7:20 | · | the global catalog of confirmed impact |
| 7:22 | · | craters, which is surprisingly small |
| 7:24 | · | given the age of the Earth. Events of |
| 7:26 | · | this scale are rare in human time |
| 7:28 | · | scales, but they are not |
| 7:29 | · | impossibilities, and understanding their |
| 7:31 | · | frequency and consequences helps inform |
| 7:33 | · | risk assessments for the future. So, |
| 7:36 | · | hats off to Earth's newest confirmed |
| 7:38 | · | impact crater. Hope you found this as |
| 7:40 | · | interesting as I did, and as always, |
| 7:42 | · | thanks for watching. |
| 7:47 | · | Before I end this video, I'd like to |
| 7:48 | · | give a big shout out to my Patreon and |
| 7:50 | · | YouTube members. Thank you so much to |
| 7:53 | · | everyone that helps to support this |
| 7:54 | · | channel. |
00:00-00:36 - The Silverpit Impact Crater Is First Discovered
