Age Screening of Deep-Sea Corals and the Record of Deep North Atlantic Circulation Change at 15.4KA

1999 ◽  
pp. 103-120 ◽  
Author(s):  
Jess F. Adkins ◽  
Edward A. Boyle
2004 ◽  
Vol 219 (3-4) ◽  
pp. 297-309 ◽  
Author(s):  
Norbert Frank ◽  
Martine Paterne ◽  
Linda Ayliffe ◽  
Tjeerd van Weering ◽  
Jean-Pierre Henriet ◽  
...  

2003 ◽  
Vol 216 (3) ◽  
pp. 399-410 ◽  
Author(s):  
Andrea Schröder-Ritzrau ◽  
Augusto Mangini ◽  
Michael Lomitschka

Nature ◽  
2013 ◽  
Vol 502 (7470) ◽  
pp. 258-258
Author(s):  
Jodie E. Smith ◽  
Michael J. Risk ◽  
Henry P. Schwarcz ◽  
Ted A. McConnaughey

2020 ◽  
Author(s):  
Finn Süfke ◽  
Frerk Pöppelmeier ◽  
Patrick Blaser ◽  
Jörg Lippold

<p>In 2004 McManus et al. published their famous <sup>231</sup>Pa/<sup>230</sup>Th record from the Bermuda Rise revealing millennial-scale changes in circulation strength back to the Last Glacial Maximum. This record marks the boost of this proxy as a kinematic circulation change proxy for the Atlantic Ocean and the initial rising slope on the ‘Elderfield-Curve’. However, the up-to-date data base of Atlantic sedimentary <sup>231</sup>Pa/<sup>230</sup>Th records gives a rather inconsistent picture of changes in the circulation strength in the Atlantic throughout the past 25 ka (Ng et al., 2018). Since both radioisotopes are strongly particle reactive it is obvious that scavenging processes may play a major role in their cycling as well. At ocean margins such processes do have a major impact on <sup>231</sup>Pa/<sup>230</sup>Th, leading to increased values and thus potentially overprinting the circulation signal. In contrast, records from open ocean sites are assumed to show a less biased circulation signal. In addition, the GEOTRACES program (Schlitzer et al., 2018) provided valuable seawater data allowing for examining the cycling of both radioisotopes under today’s circulation regime in more detail. A transect across the North Atlantic by Hayes et al. (2015) revealed that nepheloid layers contribute to strong bottom scavenging of <sup>231</sup>Pa and <sup>230</sup>Th in the northwestern Atlantic basin. Surprisingly, sedimentary core-top values do not mirror predominant scavenging effects but rather indicate a strong export of <sup>231</sup>Pa and therefore a circulation signal. With our modern proxy toolbox, it is impossible to reconstruct the occurrence and intensity of past nepheloid layers and hence their potential effect on recorded <sup>231</sup>Pa/<sup>230</sup>Th variations. Therefore, isotope-enabled models may help to better decipher the interwoven processes controlling <sup>231</sup>Pa/<sup>230</sup>Th (Rempfer et al., 2017; Lerner et al., 2019). Here an up-to-date compilation of northwestern Atlantic <sup>231</sup>Pa/<sup>230</sup>Th data will be presented. Our findings base on records covering the last 25 ka and will be interpreted in the context of recent model simulations as well as compared to seawater data. Thus, we aim for a deeper understanding of <sup>231</sup>Pa and <sup>230</sup>Th cycling in the northwestern Atlantic.</p><p>References:</p><p>Hayes, C., et al. (2015), Deep-Sea Res. Pt. II, 116, 29-41.<br>Lerner et al. (2020), Deep Sea. Res. Pt. I, 155, 1-41.<br>McManus, J. F., et al. (2004), Nature, 428, 834-837.<br>Ng, H., et al. (2018), Nat. Comm., 9, 1-10.<br>Rempfer et al. (2017), EPSL, 468, 27-37.<br>Schlitzer, R., et al. (2018), Chem. Geol., 493, 210-223.</p><p> </p>


Author(s):  
E. Le Guilloux ◽  
J.M. Hall-Spencer ◽  
M.K. Söffker ◽  
K. Olu

Although there are no previous descriptions of the habits of chirostylids in the North Atlantic, it is likely that species in the generaUroptychus,EumunidaandGastroptychushave close ecological ties with deep-sea corals since they have all been recorded in trawl samples containing corals from >200 m depth. We analysedin situdistribution ofGastroptychus formosusand potential hosts using a ROV at a range of north-eastern Atlantic sites and found that this species forms a close association with deep-sea corals that resembles the chirostylid–anthozoan associations reported in shallow Indo-Pacific waters. We update the known distribution forG. formosus, confirming that it is an amphiatlantic species that occurs along the Mid-Atlantic Ridge at least as far south as the Azores and along continental margins from the Canary Islands to Scotland at depths of 600–1700 m. The adults have very specific habitat preferences, being only found on gorgonian and antipatharian corals with a strong preference forLeiopathessp. as a host. This highly restricted habitat preference is likely to render chirostylids vulnerable to the impacts of demersal fishing both directly, as by-catch, and indirectly through habitat loss.


Nature ◽  
1997 ◽  
Vol 386 (6627) ◽  
pp. 818-820 ◽  
Author(s):  
Jodie E. Smith ◽  
Michael J. Risk ◽  
Henry P. Schwarcz ◽  
Ted A. McConnaughey

Palaeontology ◽  
2009 ◽  
Vol 52 (4) ◽  
pp. 879-931 ◽  
Author(s):  
MORIAKI YASUHARA ◽  
HISAYO OKAHASHI ◽  
THOMAS M. CRONIN

Sign in / Sign up

Export Citation Format

Share Document