19 May 2021
Dissolved methane in Belgian Coastal Waters Alberto Borges
ULiège
Introduction
19 May 2021
CH4 emission from open ocean is marginal
Introduction
19 May 2021
High organic matter deposition in sediments Why Belgian coastal waters ?
Introduction
19 May 2021
High organic matter deposition in sediments Presence of gassy sediments & peat deposits
Introduction
19 May 2021
Why Belgian coastal waters ? High organic matter deposition in sediments Presence of gassy sediments & peat deposits
Methods
Results
19 May 2021
Seasonal variations
No evidence of DMSP → CH4
0 100 200 300 400 500 0 30 60 90 120 150 180
Sediment median grain size (µm)
ZG02 780 710 700 230 215 120 130 330 Results 19 May 2021 Spatial variations
Related to sediment characteristics
« Mud » « Gravel »
Near-shore Off-shore
?
Results
19 May 2021
Spatial variations
Related to sediment characteristics
0.0 0.5 1.0 1.5 2.0 2.5 0 30 60 90 120 150 180
Sediment organic matter (%)
« Organic rich » « Organic poor »
Inputs from gassy sediments
Methods
Results 19 May 2021 Long-term changes ? 1 2 0 2 1 5 3 3 0 7 0 0 7 1 0 0 100 200 300 400 500 Station C H 4 ( n m o l L -1 ) 1990 2016 2010
Decrease of organic matter production Decrease of eutrophication since 1990
Results 19 May 2021 Future changes ? 200420052006200720082009201020112012201320142015201620172018 0 4 8 12 16 20 24
S
e
a
w
a
te
r
te
m
p
e
ra
tu
re
(
°C
)
European heatwave of 2018C H 4 ( n m o l L -1 ) Results 19 May 2021 Future changes ? European heatwave of 2018
Further Reading
Further Reading
