260:. In average, five such rings are shed each year, a number that varies considerably between years. The rings tend cross the Walvis Ridge at its deepest part, but they still lose transitional speed and many rings decay rapidly. Their transitional speed drops from 5.2±3.6 km/day to 4.6±3.1 km/day, but it is not clear how much the Walvis Ridge is responsible for this drop, since the rings' speed drops to 4.3±2.2 km/day between the Walvis Ridge and the Mid-Atlantic Ridge. The rings can cross the South Atlantic in 2.5–3 years but only two thirds make it farther than the Walvis Ridge. When the rings pass over the Cap Basin south of the Walvis Ridge they are frequently disturbed by the
20:
106:
Atlantic gradually opened, these structures became separated. The complex of seamounts in the western end of the Walvis Ridge, however, does not have a similar structure on the
American side, but there is a Zapiola Seamount Complex south of the eastern end of the Rio Grande Rise. The formation of this mirrored structure is the result of the opening of the South Atlantic some 120 Mya and the
105:
at its centre. Two of the distinct sections in the Walvis Ridge have similar mirrored regions in the Rio Grande Rise; for example, the eastern section of the Walvis Ridge evolved in conjunction with the Torres Arch (the western end of the Rio Grande Rise, off the
Brazilian coast) and, as the South
194:
Hundreds of volcanic explosions were recorded on the Walvis Ridge in 2001 and 2002. These explosions seemed to come from an unnamed seamount on the northern side of the ridge and are thought to be unrelated to the
Tristan hotspot.
287:
after which it flows west north of the
Agulhas Ridge. AABW then retroflects at the south-western end of the Walvis Ridge, flows north-east along the ridge before being retroflected south by
177:, the orientation of spreading changed, which is still visible in the orientation of the various sections of the Walvis Ridge. The mantle plume then gradually became unstable and bifurcated
680:
Lourens, L. J.; Sluijs, A.; Kroon, D.; Zachos, J. C.; Thomas, E.; Röhl, U.; Bowles, J.; Raffi, I. (2005). "Astronomical pacing of late
Palaeocene to early Eocene global warming events".
23:
The Walvis Ridge stretches some 3,000 km (1,900 mi) from the
African continental shelf to the Tristan da Cunha hotspot, separating the Angola and Cape Basins.
128:
A first 600 km (370 mi) long segment stretching from Africa to approximately longitude 6°E and varying in width between 90–200 km (56–124 mi).
167:. While the mantle plume remained large and stable, the eastern Walvis Ridge formed along with the Rio Grande Rise over the Mid-Atlantic Ridge. During the
268:, but there are fewer obstacles and disturbances west of the Walvis Ridge were the rings tend stabilise. The Agulhas rings transport an estimated 1-5
1056:
1006:
927:
284:
280:
772:
773:"Evolution of the Walvis Ridge‐Rio Grande Rise Hot Spot System: Implications for African and South American Plate motions over plumes"
536:
149:
The
Tristan-Gough hotspot track first formed over the mantle plume that formed the Etendeka-Paraná continental flood basalts some
1017:
113:, the lateral-most parts of the structure, formed at the beginning of this process in areas that are now located in
897:
Ruijter, W. P. M., de; Cunningham, S. A.; Gordon, A. L.; Lutjeharms, J. R. E.; Matano, R. P.; Piola, A. R. (2003).
736:
544:
859:"Evidence for an age progression along the Tristan-Gough volcanic track from new Ar/Ar ages on phenocryst phases"
763:
614:"Contourites at the eastern Agulhas Ridge and Cape Rise seamount shaped by Southern Ocean derived water masses"
597:
131:
A second section, 500 km (310 mi) long, stretching north–south, and narrower than the first section.
939:
242:
107:
737:"Revised plate motions relative to the hotspots from combined Atlantic and Indian Ocean hotspot tracks"
574:"Geophysical Study of the Easternmost Walvis Ridge, South Atlantic: Morphology and Shallow Structure"
288:
636:
1061:
211:
110:
537:"The Kalahari Epeirogeny and climate change: differentiating cause and effect from core to space"
78:
to an active hotspot. It is also considered one of the most important hotspot tracks because the
940:"Scientific Drilling in the South Atlantic: Rio Grande Rise, Walvis Ridge and surrounding areas"
276:
75:
637:"Evidence of explosive seafloor volcanic activity from the Walvis Ridge, South Atlantic Ocean"
1000:
921:
246:
978:
870:
829:
787:
751:
689:
651:
585:
898:
8:
982:
874:
833:
791:
755:
693:
655:
589:
845:
723:
233:
layer unique to the Walvis Ridge and is similar to the PETM, but of smaller magnitude.
184:
to produce the two separate
Tristan and Gough hotspot tracks. It finally disintegrated
94:
are the most distinctive feature of the South
Atlantic sea floor. They originated from
59:
967:"Translation, decay and splitting of Agulhas rings in the southeastern Atlantic Ocean"
613:
962:
858:
715:
435:
95:
573:
146:
in the central
Democratic Republic of Congo and Angola align with the Walvis Ridge.
74:). The Walvis Ridge is one of few examples of a hotspot seamount chain that links a
986:
878:
849:
837:
820:
795:
759:
727:
705:
697:
659:
593:
553:
261:
101:
and together they form a mirrored symmetry across the Mid-Atlantic Ridge, with the
63:
253:
156:. The eastern section of the ridge is thought to have been created in the Middle
102:
91:
79:
882:
557:
249:
215:
199:
55:
40:
857:
Rohde, J. K.; van den Bogaard, P.; Hoernle, K.; Hauff, F.; Werner, R. (2013).
815:
1050:
1032:
1019:
935:
265:
168:
799:
719:
257:
67:
991:
966:
664:
151:
58:. More than 3,000 km (1,900 mi) in length, it extends from the
51:
701:
431:
162:
186:
179:
157:
143:
710:
291:, with which it exits the Cape Basin and flows into the Indian Ocean.
220:
841:
621:
2nd Deep-Water Circulation Congress, 10-12 Sept. 2014, Ghent, Belgium
272:(millions m/s) of water from the Indian Ocean to the South Atlantic.
98:
44:
172:
816:"Middle Cretaceous sediments from the eastern part of Walvis Ridge"
269:
230:
135:
48:
896:
506:
118:
71:
960:
856:
494:
482:
470:
458:
372:
264:, interaction between rings, and bottom topography such as the
191:
and formed the guyot province in the western end of the ridge.
114:
19:
961:
Schouten, M. W.; Ruijter, W. P. M., de; Leeuwen, P. J., van;
36:
90:
Apart from the Mid-Atlantic Ridge, the Walvis Ridge and the
764:
10.1130/0091-7613(1993)021<0275:rpmrtt>2.3.co;2
226:
611:
598:
10.1130/0016-7606(1974)85<619:gsotew>2.0.co;2
571:
518:
314:
899:"On the South Atlantic Climate Observing System (SACOS)"
679:
572:
Goslin, J.; Mascle, J.; Sibuet, J.; Hoskins, H. (1974).
418:
138:
and connects the Walvis Ridge to the Mid-Atlantic Ridge.
134:
A third more discontinuous section, which is marked by
124:
The Walvis Ridge is divided into three main sections:
454:
452:
337:
310:
308:
16:
Aseismic ocean ridge in the southern Atlantic Ocean
770:
449:
343:
734:
395:
368:
366:
364:
1048:
305:
813:
384:
241:The Walvis Ridge is a natural obstacle for the
82:is one of few primary or deep mantle hotspots.
361:
735:Müller, D.; Royer, J.-Y.; Lawver, A. (1993).
1005:: CS1 maint: multiple names: authors list (
947:U.S. Science Support Program Workshop Report
926:: CS1 maint: multiple names: authors list (
780:Journal of Geophysical Research: Solid Earth
612:Gruetzner, J.; Uenzelmann-Neben, G. (2014).
229:. This period manifests as a carbonate-poor
70:, to the African coast (at 18°S in northern
634:
406:
990:
709:
663:
473:, Abstract, Introduction, pp. 21913-21914
18:
1057:Underwater ridges of the Atlantic Ocean
971:Journal of Geophysical Research: Oceans
771:O'Connor, J. M.; Duncan, R. A. (1990).
327:
325:
323:
1049:
906:Report of the CLIVAR/OOPC/IAI Workshop
578:Geological Society of America Bulletin
534:
461:, Discussion and Conclusions, p. 21933
355:
205:
934:
519:Gruetzner & Uenzelmann-Neben 2014
331:
320:
225:, about two million years after the
635:Haxel, J. H.; Dziak, R. P. (2005).
432:"Eocene Layer of Mysterious Origin"
13:
814:Pastouret, L.; Goslin, J. (1974).
14:
1073:
283:between the Agulhas Bank and the
212:Eocene Layer of Mysterious Origin
545:South African Journal of Geology
358:, Fig. 7, p. 380; Fig. 9, p. 385
227:Paleocene–Eocene Thermal Maximum
512:
500:
488:
476:
464:
424:
396:Müller, Royer & Lawver 1993
275:Originating around Antarctica,
236:
485:, Rings paths, pp. 21916-21918
412:
400:
389:
378:
349:
1:
497:, Ring Decay, pp. 21918-21919
294:
644:Geophysical Research Letters
7:
883:10.1016/j.tecto.2012.08.026
385:Pastouret & Goslin 1974
10:
1078:
558:10.2113/gssajg.110.2-3.367
527:
344:O'Connor & Duncan 1990
85:
289:North Atlantic Deep Water
111:continental flood basalts
375:, Conclusions, pp. 69-70
346:, Introduction, p. 17475
299:
800:10.1029/jb095ib11p17475
252:that are shed from the
175: million years ago
407:Haxel & Dziak 2005
317:, Introduction, p. 469
277:Antarctic Bottom Water
214:(Elmo) is a period of
202:is part of the ridge.
24:
76:flood basalt province
22:
992:10.1029/1999jc000046
963:Lutjeharms, J. R. E.
786:(B11): 17475–17502.
665:10.1029/2005GL023205
495:Schouten et al. 2000
483:Schouten et al. 2000
471:Schouten et al. 2000
459:Schouten et al. 2000
152:135 to 132
1029: /
983:2000JGR...10521913S
875:2013Tectp.604...60R
834:1974Natur.248..495P
792:1990JGR....9517475O
756:1993Geo....21..275D
702:10.1038/nature03814
694:2005Natur.435.1083L
688:(7045): 1083–1087.
656:2005GeoRL..3213609H
590:1974GSAB...85..619G
535:de Wit, M. (2007).
507:Ruijter et al. 2003
419:Lourens et al. 2005
206:Palaeoclimatic role
163:120 to 80
108:Paraná and Etendeka
315:Goslin et al. 1974
279:(AABW) enters the
187:35 to 45
180:60 to 70
60:Mid-Atlantic Ridge
25:
828:(5448): 495–496.
436:JOIDES Resolution
373:Rohde et al. 2013
1069:
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842:10.1038/248495a0
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566:
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552:(2–3): 367–392.
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318:
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262:Benguela Current
224:
190:
183:
176:
166:
160:period, between
155:
64:Tristan da Cunha
54:in the southern
1077:
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1072:
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1068:
1067:
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1062:Seamount chains
1047:
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1035:
1031:
1028:
1023:
1020:
1018:
1016:
1015:
1013:
998:
997:
977:(C9): 913–921.
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949:
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306:
302:
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254:Agulhas Current
250:warm core rings
239:
219:
208:
185:
178:
171:
161:
150:
103:Tristan Hotspot
92:Rio Grande Rise
88:
80:Tristan Hotspot
17:
12:
11:
5:
1075:
1065:
1064:
1059:
1012:
1011:
958:
932:
894:
863:Tectonophysics
854:
811:
768:
750:(3): 275–278.
732:
677:
650:(13): L13609.
632:
609:
584:(4): 619–632.
569:
531:
529:
526:
524:
523:
511:
499:
487:
475:
463:
448:
423:
411:
399:
388:
377:
360:
348:
336:
334:, pp. 2–5
319:
303:
301:
298:
296:
293:
238:
235:
218:that occurred
216:global warming
207:
204:
200:Ewing Seamount
140:
139:
132:
129:
87:
84:
56:Atlantic Ocean
15:
9:
6:
4:
3:
2:
1074:
1063:
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587:
583:
579:
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570:
559:
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551:
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460:
455:
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357:
352:
345:
340:
333:
328:
326:
324:
316:
311:
309:
304:
292:
290:
286:
285:Agulhas Ridge
282:
278:
273:
271:
267:
266:Vema Seamount
263:
259:
256:south of the
255:
251:
248:
244:
243:Agulhas rings
234:
232:
228:
222:
217:
213:
203:
201:
196:
192:
188:
181:
174:
170:
169:Maastrichtian
164:
159:
153:
147:
145:
137:
133:
130:
127:
126:
125:
122:
120:
116:
112:
109:
104:
100:
97:
93:
83:
81:
77:
73:
69:
68:Gough Islands
65:
61:
57:
53:
50:
46:
42:
38:
34:
30:
21:
1014:
1001:cite journal
974:
970:
950:. Retrieved
946:
936:Sager, W. W.
922:cite journal
910:. Retrieved
905:
886:. Retrieved
866:
862:
825:
819:
803:. Retrieved
783:
779:
747:
743:
685:
681:
669:. Retrieved
647:
643:
624:. Retrieved
620:
601:. Retrieved
581:
577:
561:. Retrieved
549:
543:
514:
509:, p. 46
502:
490:
478:
466:
439:. Retrieved
426:
414:
402:
391:
380:
351:
339:
274:
258:Agulhas Bank
240:
237:Oceanography
209:
197:
193:
148:
141:
123:
89:
32:
29:Walvis Ridge
28:
26:
1036: /
912:January 20,
356:de Wit 2007
144:kimberlites
142:Cretaceous
52:ocean ridge
1051:Categories
711:1874/11299
421:, Abstract
409:, Abstract
332:Sager 2014
295:References
281:Cape Basin
158:Cretaceous
869:: 60–71.
521:, Fig 1.A
247:mesoscale
136:seamounts
99:volcanism
45:Afrikaans
1033:26°S 6°E
965:(2000).
938:(2014).
888:June 20,
720:15944716
563:June 20,
231:red clay
66:and the
49:aseismic
47:) is an
979:Bibcode
952:May 17,
871:Bibcode
850:4176945
830:Bibcode
805:May 17,
788:Bibcode
752:Bibcode
744:Geology
728:2139892
690:Bibcode
671:May 17,
652:Bibcode
626:July 5,
603:May 17,
586:Bibcode
528:Sources
441:May 17,
119:Namibia
96:hotspot
86:Geology
72:Namibia
62:, near
1038:-26; 6
908:. NOAA
848:
821:Nature
726:
718:
682:Nature
115:Brazil
35:means
33:walvis
943:(PDF)
902:(PDF)
846:S2CID
776:(PDF)
740:(PDF)
724:S2CID
640:(PDF)
617:(PDF)
540:(PDF)
300:Notes
41:Dutch
37:whale
1021:26°S
1007:link
954:2015
928:link
914:2015
890:2015
807:2015
716:PMID
673:2015
628:2015
605:2015
565:2015
443:2015
221:53.7
210:The
198:The
117:and
43:and
27:The
1024:6°E
987:doi
975:105
879:doi
867:604
838:doi
826:248
796:doi
760:doi
706:hdl
698:doi
686:435
660:doi
594:doi
554:doi
550:110
39:in
1053::
1003:}}
999:{{
985:.
973:.
969:.
945:.
924:}}
920:{{
904:.
877:.
865:.
861:.
844:.
836:.
824:.
818:.
794:.
784:95
782:.
778:.
758:.
748:21
746:.
742:.
722:.
714:.
704:.
696:.
684:.
658:.
648:21
646:.
642:.
619:.
592:.
582:85
580:.
576:.
548:.
542:.
451:^
434:.
363:^
322:^
307:^
270:Sv
245:,
223:Ma
189:Ma
182:Ma
173:60
165:Ma
154:Ma
121:.
1009:)
995:.
989::
981::
956:.
930:)
916:.
892:.
881::
873::
852:.
840::
832::
809:.
798::
790::
766:.
762::
754::
730:.
708::
700::
692::
675:.
662::
654::
630:.
607:.
596::
588::
567:.
556::
445:.
31:(
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