Middle Holocene Sea-Level Change and Coastal Response, Texas Gulf Coast

最近由美国国家科学基金会赞助的研究得出了德克萨斯州墨西哥湾沿岸全新世中期海平面变化的新模型。这个模型表明，海平面在6800年前达到了现在的海拔，在那之后的2000年里略高于现代。这一观点与传统的解释以及另一个研究小组最近和正在进行的工作形成鲜明对比，后者认为当时的海平面低于目前的6-10米，而现在的海平面直到3000年前才达到。这一新阶段的研究将通过记录中全新世海平面变化和沿海地貌系统的响应来检验这些替代模型。地貌学、沉积学、微古生物学和地质年代学技术将被用来研究一系列新发现的地貌，这些地貌可能是检验这些海平面变化和海岸演化的不同观点的关键。德克萨斯州墨西哥湾海岸长期以来一直是研究海岸过程和地貌及其对冰川后海平面上升的响应的演变的天然实验室。这里已经发展了几个著名的海岸景观演变模型，但都是在3000年前海平面持续上升的传统观点的背景下发展起来的。记录全新世中期高位将对解释区域范围内的沿海地貌演变以及全球范围的冰量和海平面特征产生重大影响。此外，石化、航运、渔业和旅游业与目前的环境和资源分布息息相关，因此这一地区过去和未来的海平面变化不仅仅是学术上的兴趣。记录较高的海平面位置，以及随之而来的沿海反应，可以为预测不久的将来由于人为和自然气候变化而出现的海平面上升情景提供一个类比。

Recent NSF-sponsored research has resulted in a new model for middle Holocene sea-level change along the Texas Gulf Coast. This model suggests sea level reached present elevations 6800 years ago, and was slightly higher than modern for 2000 years after that. This view contrasts sharply with traditional interpretations, as well as recent and ongoing work by another research group, which would place sea level 6-10 m below present at that time, with present sea level not reached until 3000 years ago. This new phase of research will test these alternative models through documentation of middle Holocene sea-level change and the response of coastal geomorphic systems. Geomorphological, sedimentological, micropaleontological, and geochronological techniques will be used to examine a series of newly-recognized landforms that may hold the key to testing these alternative views of sea-level change and coastal evolution.The Texas Gulf Coast has long served as a natural laboratory for the study of coastal processes and landforms and their evolution in response to post-glacial sea-level rise. Several well-known models for coastal landscape evolution have been developed here, but within the context of the traditional view of continued sea-level rise until 3000 years ago. Documentation of a middle Holocene highstand would have significant implications for interpretations of coastal landscape evolution at the regional scale, as well as global-scale ice volume and sea-level signatures. Moreover, the petrochemical, shipping, fisheries, and tourism industries are linked to the present distribution of environments and resources, so past and future sea level changes in this area are of more than academic interest. Documentation of a higher sea-level position, and attendant coastal response, may provide an analog for sea-level rise scenarios that have been predicted for the near future due to anthropogenic and natural climate changes.