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However, there are lots of geological processes which can make circular or apparently circular features. Seeing a round feature on a map is not good enough to call something a crater, or even necessarily theorize about an asteroid impact. The rocks at the site have to be studied to seriously consider
226:
In 2009, there were categories with names like "Craters", "Craters by country", "Craters of Canada", etc. Those categories had instruction that they were just for impact craters. But articles for other kinds of craters were continually being added to them by well-meaning editors who either didn't
213:
The source of the confusion comes from the use of the word "crater" for several unrelated geological processes involving asteroid impacts, volcanic eruptions, or nuclear and chemical explosions. Over the years, many editors have looked at a topic and referred to it just as a "crater", leading to
204:
Categorization of craters has been a source of recurring confusion over the years on
Knowledge (XXG). This essay presents lessons learned and best practices for creating and using categories about various kinds of craters. It also includes advice on what not to categorize as a crater.
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started to fill up with a confusing mix of miscellaneous subcategories and articles again. After cleaning it out, instead of proposing to delete it, it was kept as a disambiguation category. It has specific instructions to use the specific category tree for the type of crater:
453:
edit citing the news article and claiming the new crater is confirmed. But there is always more peer review to do at that point. So
Knowledge (XXG) editors don't decide what is a confirmed impact - interpreting the evidence is just too easy to fall into a trap of
252:. They can be impact, volcanic or explosion craters, but not just craters. Otherwise it turns out to be too easy to find for editors to use tools like HotCat that only show the name of the category and none of the instructions on the category text.
239:
Cleaning up the categories and answering questions has led to some advice: 1) don't just use "crater" without a type in a category name, and 2) re-created categories were marked as disambiguation or redirect to help editors find the right category.
420:
when he found that
Arizona's Meteor Crater had the same overturned structures and shocked minerals as Nevada's nuclear test craters, only much bigger. A detailed overview of the science of impact cratering is publicly available in the
217:
There are also some geological formations and map illusions which commonly are mistaken for craters. So this page will also point out items which should not be categorized as any kind of crater, and where to put them instead.
415:
are scientifically relatively new. Understanding of the geological structure and methods to prove or disprove an impact only began to be learned in the 1960s. This subfield of geology was originally established by
590:
is medium-sized compared to other volcanic craters, and is formed by an explosive eruption when magma comes in contact with groundwater. After the eruption ends, the maar may fill with water to form a lake.
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where the surface geology is primarily driven by impacts. Depending on an astronomical body's amount of geological activity, there is little to no doubt whether a circular structure is an impact. So if
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or its subcategories. If reliable sources for geology call a structure a volcanic crater, caldera or maar, that's acceptable to call it and categorize it as a volcanic crater.
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As of 1 December 2019 this essay is still in need of more review comments before it can be moved from user essay to a subpage of
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It contains the advice or opinions of one or more
Knowledge (XXG) contributors. This page is not an encyclopedia article, nor is it one of
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decides when an impact is confirmed. Confirmed impact sites have an EID entry. The parts of the URL can then be used in
Knowledge (XXG)'s
55:
209:
The dictionary definitions of a crater require, for geological uses, that it must have been caused by some kind of explosion or eruption.
533:
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All other impact craters and structures, whether theorized or published in scientific journals and not (yet) listed in EID, go under
298:. If it had been deleted, it would eventually have been re-created too. So the redirect tells future editors the right place to go.
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There is another common confusion when the news media reports a newly-discovered impact crater. Invariably, someone makes a
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So instead of just using the word "crater", now we know to specify which of several types of geological formations we mean:
270:
Another lesson was learned 10 years after the renaming in 2019, after some of the original category names were re-created.
1113:
651:. (And let's hope there never are enough of those to make a category.) If there are lakes in other explosion craters, use
473:
422:
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so those all had "impact craters" in their names, instead of just "craters". That worked well at resolving the confusion.
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Various volcanic cones may have a small crater where debris is deposited around an eruption vent at the summit or flank.
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a type of crater. They aren't craters because they aren't the result of an explosion. They should go under
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Traces of
Catastrophe: A Handbook of Shock-Metamorphic Effects in Terrestrial Meteorite Impact Structures
59:
462:
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318:
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a crater on another astronomical body, that's an acceptable source. Use the appropriate subcategory of
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are formed by nuclear or chemical explosions on the ground or at shallow depth below the surface.
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Crater lakes have the same issues as craters, and should also be placed in qualified categories.
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Some different eruption processes cause different types of volcanic craters, large and small.
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is the only nuclear explosion crater lake. That isn't enough for a category according to
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is the largest volcanic crater, formed by a collapse of the volcano during an eruption.
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jumbled, disorganized categories containing articles and files with a mix of all kinds.
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62:. Some essays represent widespread norms; others only represent minority viewpoints.
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This doesn't currently have its own category. Use the appropriate subcategory of
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Any other kind of depression which is not a crater should be categorized under
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items establish background and consensus around categorization of craters.
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template to cite it as a reference. That automatically adds the article to
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is one of the most prominent impact craters on the visible side of the Moon
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There have been some cases of confusion by editors who wanted to call a
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which cover and erase craters, renewing the surface. Contrast with the
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categories about craters must include the type of crater in the name
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In
November 2019, two CfR discussions sorted out crater lakes into
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There is no category for explosion crater lakes. For example,
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read or didn't understand the directions. Discussion led to a
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Other formations, even if resembling craters, are considered
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671:. Cave collapses are considered sinkholes, by definition.
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Category:Impact craters on Earth by geologic time scale
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Category:Impact craters on Earth by geologic time scale
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The big lesson learned from the 2009 mass renaming was
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Lakes in volcanic craters should be categorized under
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Category:Impact craters on Earth by geological period
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Lakes in impact craters should be categorized under
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was emptied and turned into a templated redirect to
352:) impacts on astronomical bodies, including Earth.
366:resulting from volcanic eruptions include large
824:Category:Rubielos de la Cérida impact structure
796:Category:Impact craters by geologic time scale
8:
1231:Knowledge (XXG) essays about categorization
503:Impact craters on other astronomical bodies
113:the discussion on the WikiProject talk page
200:are a pair of volcanic maars in Nevada, US
773:Category:Possible impact craters on Earth
507:Earth has many geological forces such as
493:Category:Possible impact craters on Earth
445:Confirmed by citing Earth Impact Database
429:", which is available for free download.
159:is from a 1962 nuclear test explosion in
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266:Craters category kept for disambiguation
56:Knowledge (XXG)'s policies or guidelines
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244:Category name must include crater type
255:
7:
542:Category:Impact craters on asteroids
885:Category:Modern Earth impact events
682:Crater-related category discussions
848:Category:Categories by time period
534:Category:Impact craters on planets
60:thoroughly vetted by the community
28:
768:Category:Possible impact craters
640:or the appropriate subcategory.
538:Category:Impact craters on moons
296:Category:Impact craters on Earth
140:Barringer Crater, also known as
100:
33:
1195:United States Geological Survey
1165:United States Geological Survey
932:Category:Unknown origin craters
321:as a disambiguation similar to
1089:Merriam-Webster.com Dictionary
985:Category:Volcanic crater lakes
908:Category:Earth Impact Database
676:Category:Depressions (geology)
622:Category:Volcanic crater lakes
481:Category:Earth Impact Database
303:Category:Volcanic crater lakes
229:mass-renaming of 76 categories
48:Knowledge (XXG) categorization
1:
1241:User essays on categorization
1114:Lunar and Planetary Institute
880:Category:Modern impact events
423:Lunar and Planetary Institute
1013:Category:Impact crater lakes
555:should be categorized under
439:Category:Impact crater lakes
311:Category:Impact crater lakes
182:Summit crater at the top of
1140:University of New Brunswick
956:Category:Subsidence craters
467:University of New Brunswick
253:
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638:Category:Explosion craters
393:Category:Explosion craters
285:Category:Explosion craters
67:
1057:Dictionary.com Unabridged
720:Category:Craters on Earth
688:Categories for Discussion
653:Category:Artificial lakes
563:Types of volcanic craters
557:Category:Volcanic craters
379:Category:Volcanic craters
292:Category:Craters on Earth
281:Category:Volcanic craters
144:, is an impact crater in
128:is a volcanic caldera in
1106:French, Bevan M (1998).
1199:Volcano Hazards Program
1169:Volcano Hazards Program
1136:"Earth Impact Database"
487:Possible impact craters
357:Category:Impact craters
277:Category:Impact craters
1008:Category:Annular lakes
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980:Category:Crater lakes
632:Nuclear and chemical
616:Volcanic crater lakes
499:a new impact theory.
463:Earth Impact Database
427:Traces of Catastrophe
319:Category:Crater lakes
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58:, as it has not been
1160:"Glossary - Caldera"
715:Category:Astroblemes
526:planetary scientists
474:Cite Earth Impact DB
1236:WikiProject Geology
851:- including rename
433:Impact crater lakes
109:WikiProject Geology
1092:. Merriam-Webster.
805:27 September 2009
777:12 September 2009
669:Category:Sinkholes
607:Category:Volcanoes
340:are the result of
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1190:"Glossary - Maar"
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989:28 November 2019
961:10 November 2019
937:10 November 2019
889:19 December 2013
634:explosion craters
628:Explosion craters
594:Categorize under
580:Category:Calderas
578:Categorize under
456:original research
391:Categorize under
386:Explosion craters
377:Categorize under
355:Categorize under
315:Annular lakes CfR
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743:Category:Craters
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553:Volcanic craters
548:Volcanic craters
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418:Eugene Shoemaker
364:Volcanic craters
329:Types of craters
323:Category:Craters
307:Crater_lakes CfR
272:Category:Craters
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1203:. Retrieved
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172:Tycho Crater
157:Sedan Crater
85:WP:CRATERCAT
41:
1226:User essays
659:Non-craters
645:Lake Chagan
522:astronomers
425:'s e-book "
402:depressions
317:), leaving
126:Crater Lake
42:This is an
18:User:Ikluft
1220:Categories
1205:2019-10-07
1175:2019-10-07
1145:2019-10-07
1064:2019-11-06
1033:References
699:discussion
451:good faith
370:and small
222:Background
198:Soda Lakes
78:WP:CRATERS
70:Shortcuts
1122:40770730
1084:"crater"
1052:"crater"
917:✗
696:proposal
665:sinkhole
649:WP:SMALL
368:calderas
346:asteroid
20: |
1003:rename
975:rename
951:delete
927:delete
903:delete
875:rename
819:delete
791:rename
763:rename
705:result
573:caldera
509:erosion
258:below.)
184:Mt Fuji
146:Arizona
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843:reorg
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710:merge
702:closed
342:bolide
309:) and
290:Also,
161:Nevada
130:Oregon
372:maars
350:comet
313:(see
305:(see
254:(See
188:Japan
44:essay
22:essay
16:<
1118:OCLC
1025:Pass
997:Pass
969:Pass
945:Pass
921:Fail
897:Pass
869:Pass
837:Pass
813:Pass
785:Pass
757:Pass
732:Pass
588:maar
524:and
517:Moon
511:and
461:The
163:, US
148:, US
132:, US
1011:to
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1021:✓
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753:✓
728:✓
609:.
344:(
115:.
50:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
