A newly discovered submerged reef on the Miyako-Sone platform, Ryukyu Island Arc, northwestern Pacific.
A newly discovered submerged reef on the Miyako-Sone platform, Ryukyu Island Arc, northwestern Pacific.
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西北太平洋琉球岛弧宫古曾根平台上新发现的水下珊瑚礁。
DOI：
10.1016/j.margeo.2016.01.007
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发表时间：
2016
期刊：
影响因子：
2.9
通讯作者：
Y.
中科院分区：
文献类型：
--
作者：
Arai;H.;Matsuda;H.;Sasaki;K.;Machiyama;H.;Yamaguchi;T.;Inoue;T.;Sato;T.;Takayanagi;H. and Iryu;Y.
在位于太平洋西北部琉球群岛宫古岛东北部的宫古曾根平台上，利用遥控潜水器进行了测深回声仪测绘和海底观测。本研究的目的是揭示宫古曾根台地的起源和发展，这是重建琉球群岛地理演化和地质历史的关键领域。由此产生的高分辨率测深图显示了海底地貌的细节，包括平台上水下阶地的空间分布。我们在此报告在平台上发现了一个暗礁（宫古-曾根礁），其顶部水深56米，南北方向延伸长达1公里，最小宽度为500米。礁体由中央凹陷和同心边缘脊组成;边缘脊外缘沿着有类似“刺和槽”的地形特征。Miyako-Sone礁淹没在全球冰后期海平面上升期间约11-12 ka，这可能与MWP-1B在约11.5 ka。11 ka时琉球群岛海表温度的升高表明宫古曾根礁形成于冰后期较冷的末期。宫古曾根台地的一部分可能是琉球群沉积后低海平面时期陆栖生物从冲绳岛向宫古岛迁移的陆桥。
Bathymetric echosounder mapping and seafloor observations using a remotely operated vehicle were conducted on the Miyako-Sone platform, located northeast of Miyako-jima, Ryukyu Islands, northwestern Pacific Ocean. This study aims to unravel the origin and development of the Miyako-Sone platform, a key field to reconstruct the biogeographic evolution and the geologic history of the Ryukyu Islands. The resulting high-resolution bathymetric map reveals details of the seafloor geomorphology, including the spatial distribution of submerged terraces on the platform. We report herein the discovery of a submerged reef (the Miyako-Sone reef) on the platform whose top is at a water depth of 56 m, extending in a north–south direction for up to 1 km and with a minimum width of 500 m. The reef consists of a central depression and a concentric marginal ridge; topographic features analogous to “spurs and grooves” are recognized along the outer margin of the marginal ridge. The Miyako-Sone reef was drowned during a period of global postglacial sea-level rise between ~ 11–12 ka which may coincide with MWP-1B at ~ 11.5 ka. The increase in sea surface temperature in the Ryukyu Islands at ~ 11 ka shows that the Miyako-Sone reef formed during the final stage of the cooler postglacial period. Part of the Miyako-Sone platform was likely a land bridge for the migration of terrestrial organisms from Okinawa-jima to Miyako-jima during low sea-level stands after the deposition of the Ryukyu Group.