Gempa ini kemudian memicu terjadinya tsunami yang menerjang pesisir barat Sumatera dengan wilayah terdekat dari pusat gempa adalah Pariaman hingga Bengkulu. Tsunami juga menyebabkan kerusakan parah di Maladewa, Sri Lanka, dan Seychelles. Selain itu, tsunami juga dilaporkan mencapai Australia bagian utara, Teluk Benggala, dan Thailand meskipun dalam intensitas kecil. Besarnya gempa ini telah diestimasi dengan menggunakan catatan pengangkatan microatoll karang. Namun bencana ini tidak terdokumentasi dengan baik sehingga tidak diketahui dengan pasti dampak dan korbannya.
Gempa Bumi Sumatera Sebelum dan Sesudahnya
Sebelumnya pada tahun 1797, juga terjadi gempa bumi berkekuatan 8,5 sampai 8,7 Skala Richter yang juga menimbulkan tsunami di pesisir Sumatera Barat. Gempa bumi Sumatera 1797 adalah yang pertama dalam serangkaian gempa bumi besar yang pecah bagian dari segmen Sumatra dari megathrust Sunda. Hal ini menyebabkan tsunami yang sangat merusak di dekat Padang, di mana sebuah kapal Inggris 150-200 ton didorong 1 Km hingga ke pedalaman sungai Arau.
Setelah Gempa Bumi Sumatera 1833 tepatnya pada tahun 1861 terjadi Gempa bumi Sumatera berkekuatan 8,5 SR, terjadi pada tanggal 16 Februari 1861. Itu adalah yang terakhir dalam urutan gempa bumi yang berdekatan pecah bagian dari segmen Sumatra dari megathrust Sunda. Hal ini menyebabkan bencana tsunami yang menyebabkan beberapa ribu kematian. Gempa dirasakan sejauh semenanjung Malaysia dan bagian timur Jawa.
Beberapa Catatan Sejarah Gempa Bumi Sumatera
Sepanjang zona subduksi Pulau Sumatera merupakan jalur gempa bumi yang paling banyak menyerap dan mengeluarkan energi gempa bumi. Dalam sejarah, tercatat sudah banyak kejadian gempa bumi dengan magnitudo di atas 8.0 (skala Richter dll) [Natawidjaja, 2005; Newcomb and McCann, 1987]. Di Selatan Sumatera, gempa besar pernah terjadi tahun 1833 (M8.9) dan tahun 1797 (M8.3-8.7). Kedua gempa ini menghasilkan tsunami besar yang menghantam perairan Sumatra Barat dan Bengkulu.
Gempa dan tsunami besar juga pernah melanda wilayah Nias-Simelue pada tahun 1861 diperkirakan berkekuatan lebih dari 8.5 SR. Kemudian tahun 1907 terjadi kembali tsunami besar di wilayah Simelue dan Nias. Meskipun magnitudo gempa yang menyebabkan tsunami 1907 ini tidak terlalu besar (M7.6) namun tinggi tsunami yang terjadi di pantai barat dan Utara Simelue mencapai lebih dari 10 meter.
Bedasarkan catatan, tinggi tsunami tahun 1907 dua kali lebih besar dari tsunami Aceh 2004 di wilayah Pulau Simelue. Peristiwa tsunami inilah yang konon melahirkan istilah “SMONG” atau bahasa lokal untuk tsunami. Orang-orang yang selamat saat bencana tsunami 1907 itu lantas menceritakan tragedi tersebut pada anak cucu mereka, turun temurun hingga kini. Inti nasehatnya kurang lebih adalah “apabila nanti air laut tiba-tiba surut sampai jauh ke tengah maka itulah tandanya smong akan datang, larilah cepat ke bukit, selamatkan jiwa dan tinggalkan saja harta benda”.
1.From [Wichmann, 1918b], pp 94-97. (Translated by Jenny Briggs)
January 28, a few minutes after 12 noon. Batavia. Earthquakes. The shocks were repeated, gaining in severity. The last one was so strong that several houses were damaged and even the old Lutheran church developed cracks.
January 29, noon. Tjiwidei. District of Tjisondari, Division of Bandung, Preanger regency, Java. Severe quakes, one of which was followed by rumblings from the earth that lasted one minute.
November 24, around 8:30 p.m. Sumatra. Severe earthquake, that was felt in Singapore and even in Java.
In Bengkulen [Bengkulu], on the west coast of Sumatra, there were severe quakes, the first of which lasted 5 minutes4 and caused damage and even destruction of buildings. The tidal wave which crashed into the coast destroyed the harbor dam and all houses nearby. Two schooners, along with several smaller crafts, were flung onto the land.
Padang. Severe quakes, lasting 3 minutes, which recurred over the following days.
Direction SSW-NNE. Apart from the damage to buildings, cracks also appeared in the earth, from which water and “sulfurous steam” arose. Each quake was accompanied by a subterranean crashing noise. A tidal wave that broke here did considerable damage.
Indrapura and Pulu Tjingko [Cinco island]. Severe shaking. The damage caused here by the tidal wave was significant, and people also lost their lives. From the Gunung Singalang (volcano) people heard a loud boom, which, as at the Merapi volcano (which was initially blamed for the explosion), was followed by an eruption.
Priaman. The most intense quakes. Cracks of two or more feet in breadth appeared in the earth. The sea drew back and then returned in the form of a powerful tidal wave, which tore numerous ships from their anchors. The shaking continued for many days.
Province of Rau, Division of Lubuk Sikaping. The Amerongen Fort was forcibly attacked by rebellious natives during the time of the earthquake itself; they interpreted the shaking as a good sign.
Palembang. The first quake, noticed at 8:30 p.m., was followed by 6 others. Direction S-N. Buildings developed cracks and several huts collapsed.
The Ajer [Air] Lang river, whose source was at the volcano Bukit Kaba, had run dry 3 years previously when an earthquake was followed by a landslide that created a dam and a lake. During the earthquake of November 24, however, this dam was destroyed again, which emptied the lake. In their stormy course, the tumbling waters either partly or completely destroyed the village of Kapala Tjurk on Ajer Lang, as well as the more distant villages on Ajer Kling: Udjan Panas, Lubuk Talang, Ajer Apo, Lubuk Tandjung, Tabah, Njambikei and Grung Agung.
Singapore. At 8:35 p.m. a weak shock was felt, followed by a shaking of the ground that lasted for a minute or perhaps somewhat longer. The vibrations experienced in the encampment of Glam were stronger than those in the town itself. In the report it was noted that this was the first earthquake in Singapore since its occupation by the English (1819).
On Java, the quake was also weak; reports simply noted this fact.
On the high seas, the quake was also experienced. The ship “Mercurius”, which at the time was above the Pageh [Pagai] Islands on the west coast of Sumatra, was shaken by heavy quakes.
August 26. The island Ramiri on the coast of Arakan, Birma.
During the earthquake, people observing the mud volcano from Kyauk Phyu, [a town/place- J.B.] which lay off its northern peak, saw flames and steam rising several hundred feet above the volcano’s summit.
November 25, 7 a.m. Singapore. A quake, followed by a second one at 5 a.m. [sic- J.B. This may be an error in the original that should be p.m.?] Direction E-W.12 Pulu Painang (Penang). Earthquake.
2. From [du Puy, 1847], pp 156-158. Translated by Maarten Schmitt, Caltech
To the editors of the Journal of the Dutch (East) Indies
A friend and lover of the sciences has enabled me to communicate the following observation of a major earthquake, falling in the time interval between the observations of Mr. du Puij and mine.
Dr. A.F.W. Stumpff
On November 24, 1833, around 8 p.m. oscillating earthquake shocks were felt in Padang, on the W. coast of Sumatra, which at first were not thought to be serious; soon, the shocks were so violent that all went outside, fearing to be buried under the wiggling buidings. Outside, with the earth shaking under one’s feet, one saw in a bright moon buildings and trees in hefty motion, the ground splitting with water bubbling up with major force, while the river was threatening to overflow. The sea was extremely active, one was fearful of it rushing in causing destruction as had happened in a similar natural event late in the last century. This situation lasted somewhat over three minutes.
The entire population of Padang was afoot, those living along the river trying to reach higher lying areas of the city.
During the months of August, September and October one had observed extreme heat and humidity; the day of November 24 characterized itself by a deep silence in all of nature, that had not then been noticed, however; the terrible motion that followed was not without consequnces. In the houses, everything was overthrown, especially the stone houses were subject to great destruction through the tearing and separating of walls and the collapse of stone pillars. At sea there was also much commotion. Ships in the port of Padang moved on their anchors, some of which were lost.
An underground noise preceded the motion, after which mud and sulfur-like fumes rose from the split ground.
Several hours before the first shock, one had seen along the beach a surprisingly large amount of fish; the following day many dead fish were observed at the same location.
It was noteworthy that the volcano Merapi in Agam was not particularly active during this terrifying event; it had early thrown out much fire and ash but during the general upheaval the mountain was quiet; only after the first motion one had observed a terrible bang, which some here in Padang also believed to have heard.
Elsewhere, local circumstances seem to have offered more resistance to the destructive force. At Poelo Cinco [Cinco island], the sea rushed in and carried off several houses and also people.
At Indrapoera there was also some destruction caused by the sea and a few people died. At Benkoelen [Bengkulu], all buildings had much damage, so much so that the tower and the fort had to be taken down; the pier with the storage building and the customs office were wiped out, two government and several other ships were deposited on the beach, however no lives were lost there. Shocks were felt far into the ocean. The captain of the ‘Mercury’ tells that near the Pagai islands, hundreds of miles offshore, he experienced the shocks as if he had hit cliffs.
Experts are assuming that this earthquake moved from SSW to NNE. The first and strongest motion was simultaneous with spring tide, three days before Full moon. The atmosphere seems to have been little affected and weather stations saw no change. The same night and following days were characterized by shocks ofvarying strengths until the end of November.
