A newly discovered submerged reef on the Miyako-Sone platform, Ryukyu Island Arc, Northwestern Pacific

Arai, K.; Matsuda, Hiroki; Sasaki, Keiichi; Machiyama, Hideaki; Yamaguchi, Takeshi; Inoue, Takahiko; Sato, Taichi; Takayanagi, Hideko; Iryu, Yasufumi

doi:10.1016/j.margeo.2016.01.007

Cited by 18 publications

(9 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such discrepancies are a result of differences in environmental factors: primary productivity level. Moreover, migration patterns that have been discovered in the Ryukyu Trench area show that reefs and geomorphic landforms serve as land bridges for the migration of terrestrial organisms from Okinawa-jima to Miyako-jima (Arai et al 2016).…”

Section: Environmental Settingsmentioning

confidence: 99%

Using GMT for 2D and 3D Modeling of the Ryukyu Trench Topography, Pacific Ocean

Lemenkova

2021

Miscellanea Geographica

View full text Add to dashboard Cite

This research focuses on the 2D and 3D geospatial analysis of the Ryukyu Trench, a deep-sea trench located in the western Pacific Ocean between Japan and Taiwan. The aim of the research is to visualize regional differences in the topography of the southern (S) and northern (N) parts of the trench. Technically, the methodology is based on using the Generic Mapping Tools (GMT) scripting toolset, for modelling the General Bathymetric Chart of the Oceans (GEBCO), and Earth Topography and Bathymetry dataset (ETOPO1) raster grids. The results demonstrated topographic differences in the two segments. The most frequent depths lie between -5,000 and -6,000 m. The N part has steeper gradient slopes and deeper bathymetry. Of the depth differences >-6,000 m, S has nine values with depths >-6,800 m while N shows 123 records (max -7,460 m). The submarine terraces of S have gentler slopes compared with the N segment. The technical approach presents GMT-based 2D and 3D cartographic modelling aimed at visualizing regional variations of the seafloor topography.

show abstract

Section: Environmental Settingsmentioning

confidence: 99%

Using GMT for 2D and 3D Modeling of the Ryukyu Trench Topography, Pacific Ocean

Lemenkova

2021

Miscellanea Geographica

View full text Add to dashboard Cite

show abstract

“…, Jansen et al, 1986;Sepulcre et al, 2011;Gulick et al, 2015, Martinez-Boti et al, 2015MPT , , 2002Arai et al, 2016MPT , , 2006Nakamori 1986 MPT Kirschvink, 1980a;Blakemore, 1982;Chang, 1984 Stolz et al, 1986 Mc-Neill 1988 Sakai andJige 2006 Sakai andJige 2006 M-B 990 ka;Gradstein et al, 2012 M-B 6.5 10 8 7. Doan et al 19601973Ujiie and Oki 197419761976, 197819791982 .…”

Section: Mid-pleistocene Climate Transition Mptmentioning

confidence: 99%

Magnetostratigraphy of the Ryukyu Group in Miyakojima Island, Okinawa, Japan

Anai

Shibuya

Mochizuki

2017

Jour. Geol. Soc. Japan

View full text Add to dashboard Cite

The Ryukyu Group in the Ryukyu islands consists of reef limestones of Pleistocene age, and records cycles of marine regression and transgression. Study of the rocks has the potential to constrain precise sea level changes around the middle Pleistocene climate transition from kyr cycles to kyr cycles. To assign a geochronological marker in the age of the transition, we undertook magnetostratigraphic studies of the Ryukyu Group rocks exposed on Miyakojima Island. Paleomagnetic samples were collected at sites from all sequence-stratigraphic units on Miyakojima Island (MY-Units to in ascending stratigraphic order). The conventional thermal demagnetization procedure provided reliable polarity determinations for only seven sites. For the remaining sites, we developed a novel technique of reductive chemical demagnetization (RCD) combined with alternating field demagnetization. This hybrid technique successfully erased the overprinting magnetic components, revealing the primary component. Paleomagnetic directions of sites show that the lower part of the Ryukyu Group (MY-Units-, and the lowest part of MY-Unit) records reversed geomagnetic polarity, whereas the upper part (all but the lowest part of MY-Unit and MY-Unit) records normal polarity. Combining the magnetostratigraphic data with existing calcareous nannofossil data, we conclude that the reversed-normal geomagnetic polarity transition corresponds to the Matuyama-Brunhes boundary (MBB). These magnetostratigraphic data including the MBB improve the geochronology of the Ryukyu Group, which is useful for the temporal correlation between the Ryukyu Group and the other climate records during the middle Pleistocene climate transition.

show abstract

“…Although the presence of coral reefs in the Ryukyu Island Arc during glacial periods has not previously been considered, submerged reefs located near the northern limit of the coral reefs 15-30 kyr old have been reported off Irabu-jima below the seafloor at a water depth of 118 m (Sasaki et al 2006). Further, topographical studies have pointed out the existence of submerged reefs on the Miyako-Sone platform (water depth, 56 m; Arai et al 2016), off Okinawa-jima (water depth, 140 m; Arai et al 2012), and off Amami-o-shima and Kikai-jima (water depth, 110 m; Matsuda et al 2011). Around Miyakojima, modern reefs have developed only in water depths shallower than 60 m according to Obata and Tsuji (1992), and drowned reefs from the Last Glacial Maximum have been found along the isobath around 125 m (Obata and Tsuji 1992;Sasaki et al 2006).…”

Section: Introductionmentioning

confidence: 99%

New findings on submerged patch reefs and reefal carbonate rocks at water depths of 70–100 m on the insular shelf off Miyako-jima, southern Ryukyus, Japan

Inoue

Arai

2020

Prog Earth Planet Sci

Self Cite

View full text Add to dashboard Cite

Sub-bottom profiling (SBP) surveys and bathymetric mapping conducted off the shore of Miyako-jima, which belongs to the southern Ryukyus in the Ryukyu Island Arc, have revealed the presence of mound-shaped structures 3–8 m high and 50–120 m wide at depths of 70–100 m. The SBP surveys showed that the mounds possess strong distinct, convex upward reflector shapes at the top, which we interpret as submerged reefs and reefal sediments. Additionally, modern stratified sediment layers that cover these mound-shaped structures indicate that those reefs began forming and advancing shoreward in a back-stepping fashion as a result of sea-level rise. An analysis of the mound distribution shown by SBP and multibeam echo sounding (MBES) surveys suggest that they might have been formed during the lowstand stage of sea-level change, which includes the Last Glacial Period, because the distribution of these mounds is limited to water depths of 70 to 100 m, deeper than where present-day reefs grow. The SBP images hint that such high-resolution seismic profiles, accompanied by detailed bathymetric mapping off the reefal area, have the potential to provide effective indicators of not only coral reef paleoenvironment development, but also the tectonic setting of this offshore area.

show abstract

A newly discovered submerged reef on the Miyako-Sone platform, Ryukyu Island Arc, Northwestern Pacific

Cited by 18 publications

References 34 publications

Using GMT for 2D and 3D Modeling of the Ryukyu Trench Topography, Pacific Ocean

Using GMT for 2D and 3D Modeling of the Ryukyu Trench Topography, Pacific Ocean

Magnetostratigraphy of the Ryukyu Group in Miyakojima Island, Okinawa, Japan

New findings on submerged patch reefs and reefal carbonate rocks at water depths of 70–100 m on the insular shelf off Miyako-jima, southern Ryukyus, Japan

Contact Info

Product

Resources

About