气候变化领域集成服务门户(CCPortal): Hydrologic Controls of Methane Dynamics in Karst Subterranean Estuaries

CCPortal

DOI	10.1029/2018GB006026
	Hydrologic Controls of Methane Dynamics in Karst Subterranean Estuaries
	Brankovits D.; Pohlman J.W.; Ganju N.K.; Iliffe T.M.; Lowell N.; Roth E.; Sylva S.P.; Emmert J.A.; Lapham L.L.
发表日期	2018
ISSN	0886-6236
EISSN	1944-9224
起始页码	1759
结束页码	1775
卷号	32 期号:12
英文摘要	Karst subterranean estuaries (KSEs) extend into carbonate platforms along 12% of all coastlines. A recent study has shown that microbial methane (CH 4 ) consumption is an important component of the carbon cycle and food web dynamics within flooded caves that permeate KSEs. In this study, we obtained high-resolution (~2.5-day) temporal records of dissolved methane concentrations and its stable isotopic content (δ 13 C) to evaluate how regional meteorology and hydrology control methane dynamics in KSEs. Our records show that less methane was present in the anoxic fresh water during the wet season (4,361 ± 89 nM) than during the dry season (5,949 ± 132 nM), suggesting that the wet season hydrologic regime enhances mixing of methane and other constituents into the underlying brackish water. The δ 13 C of the methane (−38.1 ± 1.7‰) in the brackish water was consistently more 13 C-enriched than fresh water methane (−65.4 ± 0.4‰), implying persistent methane oxidation in the cave. Using a hydrologically based mass balance model, we calculate that methane consumption in the KSE was 21–28 mg CH 4 ·m −2 ·year −1 during the 6-month dry period, which equates to ~1.4 t of methane consumed within the 102- to 138-km 2 catchment basin for the cave. Unless wet season methane consumption is much greater, the magnitude of methane oxidized within KSEs is not likely to affect the global methane budget. However, our estimates constrain the contribution of a critical resource for this widely distributed subterranean ecosystem. ©2018. American Geophysical Union. All Rights Reserved.
英文关键词	anchialine ecosystem; carbon cycling; coastal aquifer; hydrobiogeochemistry; methane; subterranean estuary
语种	英语
scopus关键词	aquifer; biogeochemistry; carbon cycle; carbonate platform; coastal zone; concentration (composition); dry season; food web; hydrological regime; karst; methane; microbial activity; stable isotope; subterranean environment; wet season
来源期刊	Global Biogeochemical Cycles
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/129770
作者单位	Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX, United States; Now at Woods Hole Coastal and Marine Science Center, U.S. Geological Survey, Woods Hole, MA, United States; Now at Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, United States; Woods Hole Coastal and Marine Science Center, U.S. Geological Survey, Woods Hole, MA, United States; Lowell Instruments, North Falmouth, MA, United States; Onset Computer Corporation, Bourne, MA, United States; Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, United States; Moody Gardens Aquarium, Galveston, TX, United States; Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, MD, United States
推荐引用方式 GB/T 7714	Brankovits D.,Pohlman J.W.,Ganju N.K.,et al. Hydrologic Controls of Methane Dynamics in Karst Subterranean Estuaries[J],2018,32(12).
APA	Brankovits D..,Pohlman J.W..,Ganju N.K..,Iliffe T.M..,Lowell N..,...&Lapham L.L..(2018).Hydrologic Controls of Methane Dynamics in Karst Subterranean Estuaries.Global Biogeochemical Cycles,32(12).
MLA	Brankovits D.,et al."Hydrologic Controls of Methane Dynamics in Karst Subterranean Estuaries".Global Biogeochemical Cycles 32.12(2018).