Are you a beach buff?
When was the last time you went swimming in the beach?
Have you been to one of the many impressive beaches and coastal stretches of Eastern Samar Province?
Well, if not, I suggest that you read this article hoping that we may be able to change your current perspective and be acquainted on how nature has sculpted our evolving coastal environment through thousands, if not millions of years.
Why Eastern Samar?
It’s because the province has a multiform and diverse coastal features that have been created by nonstop wave actions emanating from the open seas of Pacific Ocean, providing its coastal margins with dramatic landscape to behold.
What this article hopes to impart as well, is to let everyone know that our coastal environment is a hot spot for various hazards and we, as humans must not challenge the incessant dynamic processes it is undergoing.
Current Status of Some of the Country’s Coastlines
Most of the beautiful beaches in the country attract humans and some of them choose to congregate or stay proximal to these fragile environments since they provide various sources of livelihood and recreation.
Consequentially, living near the coastlines endangers human lives and properties because these areas are prone to numerous hazards like coastal erosion, tsunami, and storm surge. Another alarming scenario facing our coastal fronts today is the likelihood of mushrooming of vertical structures such as high rise condominiums, with some even reclaiming lands to accommodate such structures. As a consequence, these establishments will be expected to source their water supply either from ground water, or from surface water, hence the threat of land subsidence and salt water intrusion due to excessive withdrawal of groundwater. These should not be taken for granted.
Providentially, this is not a common scenario in most of the remarkable coastal facade in Eastern Samar. A good number of the coastal fronts in the province remain undeveloped, unpolluted and away from human incursions.
It’s now high time to institute managing our coastlines to protect everyone’s interest or else, face the wrath of nature.
Imagine nature crushing large chunks of lands (ex. headlands) into smaller ones (ex. stumps), then to very minute particles such as sands. Do you think human can beat that?
Nothing, not even a structure or edifice made up of the sturdiest steel or toughest building material, can defy the existing laws of nature along our coastal fronts. Even hard rocks which are naturally embedded beneath the surface of the earth have no match to the simple hammering of strong waves. What more can we expect when climatic extremes such as storm surges or tsunamis brought by the so called Global Warming/Climate Change hit?
Whether it is now the norm or that the “Theory of Catastrophism” (a geologic theory that the Earth has been affected in the past by sudden, short-lived, violent events, possibly worldwide in scope-wikipedia) exists, the best option is to be pro-active than be flattened again.
Let’s make the devastating effects of catastrophic events, such as Yolanda/Haiyan typhoon in 2013 and Tohoku’s (Japan) tsunami in 2011, never to happen again in our lifetime. As a rule, no adverse impact will rise to the level of a disaster if it occurs in an area without vulnerable population.
Now, take a look at the photographs below taken during the conduct of Coastal Geohazard Mapping in the Province of Eastern Samar and be fascinated how these visually striking coastal erosional formations found in Eastern Samar province were formed via the course of nature.
Headland / Promontory and Bay / Cove
The headlands as portrayed in the above photo are outcrops of limestone jutting out into the sea and surrounded by water on three sides. These coastal features were formed as a result of coastal erosion and the tremendous battering power waves of the Pacific Ocean. This is found in Brgy. Bakayawon, Llorente, Eastern Samar.
On the other hand, the almost circular bay which is encircled by land on three sides was formed when a weaker rock that consist of sandstone, was attacked by the approaching waves in parallel direction.
Headlands are susceptible to erosion. The approaching waves tend to hit headlands first, since they stand out from the rest of the coast. Over time, other features such as caves, arches, stacks and stumps may develop on headlands and these constant modifications are exemplified in the succeeding photographs taken in the province.
Cave
The formation of the cave photographed above could be due to a combination of chemical abrasion and mechanical erosion. Acidic water seeps into crevices and other zones of weaknesses in the limestone and in the process dissolving the rock, initially forming small opening. During high tide or extreme weather conditions, this opening is attacked by strong waves creating larger opening and eventually forming a cave. This coastal erosional process takes thousands if not millions of years to take place. This cave is found in Brgy. Tabok , Llorente, Eastern Samar.
When rainwater picks up carbon dioxide from the air and as it percolates through the soil, it turns into a weak acid. Acid slowly dissolves out the limestone along the joints, bedding planes and fractures, some of which become enlarged enough to form caves (Natural Environment Research Council, British Geological Survey). This process of cave formation is called chemical erosion.
Sea cave are formed when strong waves produce fissures in the rock surface. Over a period of time, the fissures become larger, eventually forming sea caves. This process of cave formation is referred to as mechanical abrasion/hydraulic action.
Sea Arch
The red encircled natural opening is called an arch and is found in Brgy. San Miguel, Llorente, Eastern Samar. The arch is the next stage from a cave.
Due to the great force of the sea waves, the sides of the cave will gradually widen and deepen until it cuts through, turning sea cave into an arch. Sea arches stay exceptionally shorter on a geological time scale. Most of these collapse within tens or hundreds of years only.
Sea Stack
A sea stack is an isolated pinnacle or tall column of rock with rough or fractured faces such as the one depicted in the above photo. This is located off the coast of Brgy. Omawas, Maydolong, Eastern Samar. A sea stack is the next stage from an arch.
When arch becomes larger and can no longer support the keystone (top/roof of the arch), it collapses, leaving behind the base or the foot of the arch, which is now called a stack. Or if the other half of the arch is less resistant than the other side, the less resistant one breaks down faster, leaving one side to become a sea stack.
Stump
A group of sea stumps photographed along the nearshore of Brgy. Kansilides, Hernani, Eastern Samar are shortened sea stacks that have been eroded away by wave action. When the cave wears through the headland, an arch forms. Further erosion causes the arch to collapse, leaving the pillar of hard rock standing away from the coast and a stack forms. Eventually, erosion will cause the stack to collapse, leaving a stump.
Sea Cliff / Buff
Rock falls along the base of a limestone cliff in Hernani, Eastern Samar. This portion of the beach is a hazard prone area.
Resistant rock such as limestone that form very steep or vertical slope is called a cliff.
Cliffs along the coasts are formed through tectonic activity, water movement, and weathering and erosion activity. Earthquakes and landslides also form cliffs.
A vegetated buff made up of sandstone is seen protruding on one portion of the National Highway which is within the territorial jurisdiction of San Julian municipality in Eastern Samar.
The less resistant rock such as sandstone that forms a gentler slope is called a buff.
Wave-cut Notch
Above photo is an example of wave cut notch, an area of erosion at the base of a limestone cliff formed by waves. This coastal feature is found in Llorente, Eastern Samar.
The eastern seaboard of Eastern Samar province is still geologically young and in the process of assuming a stable configuration. The presence of the above coastal erosional features attests to this conclusion. In this situation, incessant creation of landforms through erosion and deposition are to be expected so we must treat these God-gift natures with utmost conscientiousness.
By: Marine Geological Survey Division