Publication Date:
2017-12-12
Description:
The response and recovery of barrier islands to extreme storms and ultimately to relative sea-level rise depends on the
height and extent of the foredunes relative to storm surge. The impact of storms is complicated by the tendency of dune
morphology to vary alongshore at a range of spatial scales, and it is reasonable to assume that this variable response will
be preserved within subsurface stratigraphy. We used ground-penetrating radar (GPR) and vibracores to investigate
subsurface structures for foredunes of different heights within a 2.5-km section of beach at Padre Island National
Seashore, Texas. Identical, laterally continuous radar reflectors were observed at each site at a depth of ~1.2 m and
interpreted as a storm surface. Results from the smallest dune suggest that the dune experienced little net erosion
during the storm but also exhibited the least recovery. The intermediate dune was completely eroded by the storm but
also exhibited the greatest recovery through the migration of accretionary mounds driven by aeolian transport, leading
to the development of embryo dunes forming the modern dune core. The largest dune was scoured at the base and
experienced little poststorm recovery, except for beachface recovery. Thus, the response and recovery of adjacent, but
morphologically distinct, dunes is quite different over the same sequence of storm activity. We suggest that the extent
and form of beach-dune recovery is dependent on the impact scale of the storm and may represent a reinforced process
once alongshore variations in dune height are initialized.
Type:
Article
,
PeerReviewed
Format:
text
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