255
the scars of sea-level rise and sea-level fall, and delve back in history to a time
before photos and tide gauges to find out the elevation of the sea top and the location
of its edge? Can we parse out the conditions that are tied to those rises and falls?
Where, one must ask, have those raindrops been? What is their story?
The story starts here and now, in the processes that govern the time and place of
the watery edge. As this book has taught us, “the present is the key to the past.”
What is showing, and growing, and flowing, here and now, leaves the same tracks,
the remnants of showing, and growing, and flowing, in the same style and with the
same patterns of marks that it did one, 1000, and 1,000,000 years ago. The smear of
mud in a rainstorm today can be seen in a mud flat that lithified a million years ago,
and the laws of uniform processes illuminate the past by the same natural algorithms at work today, and tomorrow. The past is also the key to the future, and this
book shows us where the trajectory of current conditions may take us.
The marks of sea level are left in the ebb and flow of currents, as surges inundate
and seas transgress, evidenced in a swash of sand grains, a size-sorted shell collection, or a deluge of silt. Plants and animals, large and small, find their niche at the
water’s edge, carve out a habitat in the narrow and specific conditions at that edge,
grow and die at that edge. Their remains – a fossil shell, a drowned saltmarsh, a
coral reef – mark the spot where they lived, exactly at sea level. The juxtaposition
of sea, sky, and land is traceable by the marks of physics and chemistry and biology:
the flow, the composition, the residents, are all unique to the special zone of
earthskysea.
Our researchers have examined the settings of coastal water, here and now, there
and then, and learned the patterns that repeat, new and old, now and then, always
and forever.
The “now” pattern might detail the range of droplets riding a catastrophic 2004
Indonesian tsunami via a microscopic foraminifera (foram) shell, lifted from an
offshore assemblage and dropped two kilometers inland from the coast, and mirrored by a mangrove-dwelling foram then deposited offshore. Perhaps 1200 years
ago one of these same droplets rushed past a North Carolina barrier island, this time
ferocious from the power of a major storm, so energetic that instead of dropping
seaward foram shells it stole them away and didn’t stop and drop until many miles
inland. Perhaps thousands of years before that, it froze as a snowflake, fluttering
onto great growing ice sheets during a time when humans were spearing wooly
mammoths to eat, and resting there for centuries until the climate turned, melting
the snowflake – now compressed by the weight of billions of overlying flakes, and
caked into a glacier sliding forward, grinding rocks and trees and dropping sediments carried from afar along its path – that at last trickled back to the sea. Perhaps
the now-melted snowflake churned across the sea to a coral reef, unencumbered
now by sands and shells to wash past the tentacles of a single coral polyp, bearing
nutrients that the polyp would pile onto a reef at the edge of sky and sea.
Water molecules spend thousands of years washing back and forth in the ocean,
busily rearranging the coastlines, quietly stacking up muds and deltas and dunes and
loudly tearing apart cliffs and ledges, feeding corals and marshes and mangroves.
Together, those droplets – trillions upon trillions upon trillions – add up to a sea
15 The Water, the Coast, the Future
the scars of sea-level rise and sea-level fall, and delve back in history to a time
before photos and tide gauges to find out the elevation of the sea top and the location
of its edge? Can we parse out the conditions that are tied to those rises and falls?
Where, one must ask, have those raindrops been? What is their story?
The story starts here and now, in the processes that govern the time and place of
the watery edge. As this book has taught us, “the present is the key to the past.”
What is showing, and growing, and flowing, here and now, leaves the same tracks,
the remnants of showing, and growing, and flowing, in the same style and with the
same patterns of marks that it did one, 1000, and 1,000,000 years ago. The smear of
mud in a rainstorm today can be seen in a mud flat that lithified a million years ago,
and the laws of uniform processes illuminate the past by the same natural algorithms at work today, and tomorrow. The past is also the key to the future, and this
book shows us where the trajectory of current conditions may take us.
The marks of sea level are left in the ebb and flow of currents, as surges inundate
and seas transgress, evidenced in a swash of sand grains, a size-sorted shell collection, or a deluge of silt. Plants and animals, large and small, find their niche at the
water’s edge, carve out a habitat in the narrow and specific conditions at that edge,
grow and die at that edge. Their remains – a fossil shell, a drowned saltmarsh, a
coral reef – mark the spot where they lived, exactly at sea level. The juxtaposition
of sea, sky, and land is traceable by the marks of physics and chemistry and biology:
the flow, the composition, the residents, are all unique to the special zone of
earthskysea.
Our researchers have examined the settings of coastal water, here and now, there
and then, and learned the patterns that repeat, new and old, now and then, always
and forever.
The “now” pattern might detail the range of droplets riding a catastrophic 2004
Indonesian tsunami via a microscopic foraminifera (foram) shell, lifted from an
offshore assemblage and dropped two kilometers inland from the coast, and mirrored by a mangrove-dwelling foram then deposited offshore. Perhaps 1200 years
ago one of these same droplets rushed past a North Carolina barrier island, this time
ferocious from the power of a major storm, so energetic that instead of dropping
seaward foram shells it stole them away and didn’t stop and drop until many miles
inland. Perhaps thousands of years before that, it froze as a snowflake, fluttering
onto great growing ice sheets during a time when humans were spearing wooly
mammoths to eat, and resting there for centuries until the climate turned, melting
the snowflake – now compressed by the weight of billions of overlying flakes, and
caked into a glacier sliding forward, grinding rocks and trees and dropping sediments carried from afar along its path – that at last trickled back to the sea. Perhaps
the now-melted snowflake churned across the sea to a coral reef, unencumbered
now by sands and shells to wash past the tentacles of a single coral polyp, bearing
nutrients that the polyp would pile onto a reef at the edge of sky and sea.
Water molecules spend thousands of years washing back and forth in the ocean,
busily rearranging the coastlines, quietly stacking up muds and deltas and dunes and
loudly tearing apart cliffs and ledges, feeding corals and marshes and mangroves.
Together, those droplets – trillions upon trillions upon trillions – add up to a sea
15 The Water, the Coast, the Future