Kamis, 28 Februari 2013

NASI JAGUNG, Variasi Pengganti Beras

NASI JAGUNG, Variasi Pengganti Beras

Selasa, 03 Juli 2012

NASI JAGUNG
SURABAYA - Mungkin beberapa saat pernah terlintas di pikiran kita, betapa jenuhnya menatap ke atas piring makanan kita, dan menemui fakta bahwa di sana (lagi - lagi) terhidang Nasi Putih. Makanan pokok yang memang sudah sangat tidak asing bagi kita sehari - hari. Entah sudah berapa hari kita menjejakkan kaki di atas dunia ini, dan sejak saat itu pula petualangan kita akan Nasi dan Beras terus terjaga bahkan hingga tiga kali sehari

Tapi apakah pernah terlintas di pikiran kita, dan kita berandai - andai kalau sesekali yang terhidang di atas piring kita bukaNasi lagi, melainkan sesuatu yang berbeda?


Mungkin setelah sebelumnya saya membahas tentang Sego TIWUL, tidak ada salah nya jika saya juga membahas tentang salah satu alternatif makanan pokok selain Beras / Nasi yakni Sego JAGUNG yang terkenal dengan berbagai nama. Mungkin di antara beberapa makanan pokok alternatif lainnya, kita lebih familiar dengan Nasi Jagung yang juga sering disebut dengan sebutan Sego / Nasi Empog.




Dan Nasi Jagung lebih mudah kita jumpai di lingkungan kita, bahkan tidak jarang penjual Nasi juga banyak menjual Nasi Jagung yang sangat nikmat ketika disantap hangat mengepul ini. Biasanya sayur yang lazim ditemui bersanding dengan menu Nasi Jagung adalah urap sayur, tumis terong, tumis lodeh, atau tumis cabe hijau. Sedangkan lauknya adalah ikan asin, dan rempeyek teri.
Jika kita berbicara tentang kelezatan, dan menu Nasi Jagung, gambaran seperti yang di atas itulah yang akan kita temui. Tetapi apakah kita tahu sejatinya kandungan gizi apa saja yang terkandung di dalam Nasi Jagung yang saya sebut sebagai salah satu bahan makanan alternatif pengganti Beras ini?
Berdasarkan data dari Direktorat Gizi Departemen Kesehatan, Jagung Giling Kering ternyata memiliki keunggulan gizi apabila dibandingkan dengan Beras (nah lohhh....), walaupun tidak bisa dipungkiri pula bahwa Jagung memiliki kandungan Karbohidrat yang sedikit lebih rendah apabila dibandingkan dengan Beras. Ternyata Karbohidrat sebanyak 72,4 gram terkandung dalam setiap 100 gram Jagung Giling, sedangkan Beras memiliki Kandungan Karbohidrat sebesar 78,9 gram (berbeda sekitar 6,5 gram). 
JAGUNG GELONDONGAN
Apabila kita memperhitungkan kandungan Protein di dalam Jagung Giling, pada takaran sama Jagung Giling mengandung 8,7 gram protein, sementara beras giling mengandung 6,8 gram protein. Dari sini bisa diambil kesimpulan bahwa mengkonsumsi Jagung ternyata tidak mengurangi asupan gizi di dalam tubuh kita, malah, mengonsumsi Sego Jagung sebenarnya jauh lebih baik daripada Beras karena gizinya lebih lengkap.
Selain sebagai sumber utama Karbohidrat, bahan pangan pokok yang sering diidentikkan sebagai makanan pokok orang Madura ini mengandung zat gizi lain seperti: Energi (150,00 kal), Protein (1,600 g), Lemak (0,60 g), Karbohidrat (11,40 g), Kalsium (2,00 mg), Fosfor (47,00 mg), Serat (0,40 g), Besi (0,30 mg), Vit A (30,00 RE), Vit B1 (0.07 mg), Vit B2 (0,04 mg), Vit C (3,00 mg), Niacin (60 mg).
Itulah kehebatan Sego Jagung yang mungkin juga identik sebagai jajanan dibandingkan sebagai makanan pokok (melengkapi anggapan umum orang Indonesia bahwa: "Makan belum kenyang tanpa kehadiran Nasi"). Di luar sederetan kandungan gizi yang saya sebutkan di atas, ternyata Jagung Giling juga telah diteliti secara seius oleh Dunia Medis. Bahkan mengkonsumsi Nasi Jagung / Jagung Giling disinyalir merupakan dapat membangun serta memperkuat Otot dan Tulang. Nasi Jagung juga memberikan asupan gizi yang baik bagi otak dan sistem syaraf serta dapat mencegah konstipasi. 
Dengan segenap kelebihan penting di atas, mengkonsumsi Nasi Jagung ternyata juga bisa menurunkan resiko penyakit kanker, dan jantung, dapat mencegah gigi berlubang, dan minyak yang terkandung di dalam Nasi Jagung dapat menurunkan kandungan kolesterol di dalam darah. nahh.... Nasi Jagung pun bisa diperhitungkan sebagai makanan pokok pengganti Beras bagi penderita Diabetes, karena kandungan Karbohidrat Nasi Jagung lebih rendah daripada Nasi Putih / Beras sehingga kadar gula darah dapat terkontrol.
Hebat kan salah satu makanan pokok khas nenek Moyang kita ini. Mungkin tidak ada salahnya jika kita mengikuti pola makan orang Desa yang masih memegang teguh kebiasaan Lama ini. Orang Desa terbiasa untuk memberikan variasi dalam menu sehari - hari mereka, mereka tidak seperti orang kota yang melulu memakan Nasi Putih sehari - harinya. Orang Desa terkadang mereka bervariasi dengan menghidangkan Nasi Tiwul, Nasi Jagung, bahkan Gatot (akan saya bahas di artikel berikutnya), saya sendiri menyaksikan bagaimana dalam 1 minggu mereka bisa mem - variasi makanan - makanan itu menjadi makanan pengganti Beras. Bahkan saya sendiri yang memang berasal dari salah satu Kota Kecil (Lumajang), dan sangat sering menginap di desa, lebih menikmati variasi makanan ini.
Dan memang tidak bisa dipungkiri, bahwa secara kesehatan fisik, dan bentuk fisik, masyarakat Pedesaan yang sering mengkonsumsi makanan secara bervariasi lebih bagus apabila dibandingkan masyarakat perkotaan yang melulu menyantap Beras / Nasi Putih sebagai menu harian mereka. 
Apakah Anda berminat untuk mencoba Tips Makanan Pokok Alternatif ini?

Sabtu, 23 Februari 2013

Dicari, Sarjana Pertanian Masa Depan

Dicari, Sarjana Pertanian Masa Depan
 Foto: dok. Koran SI
JAKARTA - Selama ini, ilmu pertanian masih dianggap sebelah mata. Padahal, kedaulatan dan martabat sebuah bangsa juga turut ditentukan dengan kedaulatan pertaniannya.

Guru Besar Institut Pertanian Bogor (IPB) Roedhy Poerwanto menyayangkan masih banyaknya pertanyaan dari para akademisi tentang pentingnya pendidikan tinggi pertanian. Padahal, kata Roedhy, Indonesia masih sangat membutuhkan pendidikan pertanian untuk menangkal kekuasaan asing pada pertanian Tanah Air.

"Seperti dengan adanya slogan more than just agriculture, keinginan sebagian staf IPB untuk menjadikan IPB sebagai universitas, dan beberapa Rektor PTS ingin menutup fakultas pertanian," kata Roedhy seperti dikutip dari keterangan tertulis IPB kepada Okezone, Jumat (4/5/2012). 

Roedhy memaparkan, sekira 75 persen pekerja sektor pertanian adalah lulusan SD atau yang tidak lulus SD. Lulusan SMP yang menjadi petani ada 15 persen, sembilan persen lulusan SMA, dan hanya satu persen yang memiliki gelar sarjana. Menurut Roedhy, dunia pertanian Indonesia membutuhkan sosok, baik individu maupun lembaga, yang dapat menginspirasi pelajar mendalami pertanian.

Pada 1952, kata Roedhy, pidato Bung Karno menginspirasi para siswa untuk belajar pertanian. Saat itu, Bung Karno menyeru para pemuda Indonesia, bahwa  studi ilmu pertanian dan kehewanan tidak kurang pentingnya dari studi-studi lain, tidak kurang memuaskan jiwa yang bercita-cita dari pada studi yang lain-lain

"Indonesia membutuhkan para sarjana pertanian masa depan, yakni mereka yang menguasai keilmuan pertanian, mempunyai kemampuan dalam 'operasi' pertanian, mempunyai pengetahuan mutakhir terkait dengan bisnis dan teknologi pertanian, mampu memanfaatkan sumber daya informasi, berkarakter dan berbudaya, mengenal, menjiwai dan mencintai pertanian dan lingkungannya, serta berjiwa wirausaha," imbuhnya.

Roedhy juga menegaskan posisi pertanian sebagai penentu kedaulatan dan martabat bangsa. Menurut Roedhy, pertanian yang stabil akan menjadi fondasi sebuah negara dianggap sebagai bangsa dengan sosial dan politik yang stabil pula.
"Negara besar yang tidak mampu menyediakan pangan yang cukup bagi masyarakatnya akan hancur," ujarnya menegaskan.(rfa)

About Batak Weaving

About Batak Weaving
The Batak people of Northern Sumatra have a history of weaving Ulos ni tondi (Cloth of the Soul) for ritual & ceremonial purposes that dates back to their earliest history. Batak myth tells that Lake Toba is the centre of the Earth & that the Batak are descendants of the first humans. The Toba Batak People live on Samosir Island & around the shores of Lake Toba.

Weaving is still a vital and imporant part of the Batak way of life.

Traditional Toba Batak Ulos (cloth) is hand made on a body tension (back strap) loom using hand dyed thread. Often villages produce only one or two Ulos designs, slight variations are seen between weavers.  Some pieces have limited availability.  Natural dyes are used in combination with commercial dyes. Twinning & braiding are techniques specifically used by the Batak. Women are the traditional weavers, children and men assist in twinning and spooling. Ulos have ritual & ceremonial meaning and are worn as head, shoulder or hip cloths. Batak people are proud of and cherish their own personal Ulos and weaving traditions.

Today you can see a fabulous array of personal Ulos being worn at ceremonies and celebrations, or being used as everyday carrying cloths and clothing.

A young weaver caries on tradition, village children show great interest in preservation of these skills.

Weaving village
Traditionally and to this day Ulos form part of a family's assests. Ulos are brought out and worn or displayed during ceremonies, used as dowry items and exchanged during ceremonies. Batak families keep a careful eye on which clan donates what type of Ulos and give certain Ulos back in exchange in a very formal, ritualized set of ceremonies. as a family asset, these textiles were sometimes sold to raise cash for education, funerals, weddings etc.




About Goldfish Arsik (ikan mas arsik)

About Goldfish Arsik (ikan mas arsik)

Goldfish Arsik (ikan mas arsik) – our Menu this Saturday afternoon is Ethnic Cuisine Batak (North Sumatra), arsik goldfish is also often expressed in adata hobo party. This is one dish that required every household menu Batak people either still live at home or who had to leave. A new Batak woman thumbs up as a good cook if the food was delicious and worth arsiknya served to the guests.

This is generally used for cooking arsik goldfish. This fish was chosen because goldfish live in clear water and swim forward in the group without colliding with each other. Philosophy are those who eat these fish will live in harmony, to the upstream and downstream, until the end of the pillars of his age. For the daily menu, okay we replace it with goldfish other freshwater fish such as tilapia, catfish or tilapia.
Resipes of Goldfish Arsik
Material:
- 1 tailed goldfish, clean the scales, and entrails ingsang -
- Water lime juice 1 tbsp -
- Tomato red two pieces, cut so 4 -
- Citronella two sticks, crushed -
- Andaliman 2 tsp -
- Water 150 ml -
- Onion hobo 50 grams, discard the leaves -
- Flowers Etlingera elatior one fruit -
- Santan 50 ml -
Spices:
- Chili seven fruit -
- Onion 4 bitur -
- 2 cloves garlic -
- Pecan two points -
- Turmeric 3 cm -
- Ginger 2 cm -
- Salt to taste -
Method:
1. Marinate the fish with lime juice, let stand for 15 minutes, drain.
2. Marinate the fish with spices to cover all parts of the fish.
3. Prepare a frying pan and place the flowers Etlingera elatior citronella based frying pan. Put gold fish, add water, salt, sugar, coconut milk and andaliman, stir well.
4. Simmer until cooked fish and seasoning to absorb.
5. Add the tomato and onion hobo, cook hinggakuah slightly thickened, remove from heat.
6. Serve immediately.

Tangkuban Perahu



History of Mountain " Tangkuban Perahu "

 

 

 

Long time ago in west java lived a woman, named a Dayang Sumbi. She lived alone in forest. Named Dayang Sumbi. She lived alone in a forest. One day Dayang Sumbi was quilting when suddenly , her quit fell off from her house. Then  she prayed Gods. " if a man picks up my quilt, he will be my husband. if a woman she will be my husband." Then  a male dog picks it up. For keeping her words, Dayang Sumbi married the

Dog and called him Tumang. Dayang Sumbi gave birth to a baby, named him sangkuriang, but never told him who his father was.

One day, Sangkuriang was hunting with Tumang in the forest  and he found nothing. He blamed Tumang for the failure and killed him. When Dayang Sumbi knew that, she hit Sangkuriang's head with a big spoon and asked him to go.

Many year later,  the wondering Sangkuriang found a house forest, and an old beautiful found woman  was the house in the house. The woman, Dayang Sumbi, recognized the adventure as Sangkuriang. Sangkuriang forced her to marry  him and Dayang Sumbi asked him to make vast boat in one night. In the night, Sangkuriang called his friends, ghosts and forest fairies, to help him. Dayang Sumbi feared the boat could be finished on time, so she asked some women nearby to  help her. The women hit the grains with grain punchers to make noises wich disturbed the ghosts and the fairies ran away before completing the boat upside down, and it turned into a mountain called "Tangkuban Perahu. it means the downside boat, wich stood in the north of Bandung.

Batu Gantung and Parapatan city Legend

Batu Gantung and Parapatan city Legend
                                               
Once upon a time at Toba Lake, which is famous with its legend and beautifull sightseeing, there was a family who live around the place. They live in an isolated village. The family work as farmers. Their fields are at the edge of a lake.
They used to work on their fields and plants which the products could fulfill their daily needs. This family had a beautiful daughter named Arum. People said, the beauty of the girl was so famous so that many young men tried to persuate her to become their girlfriend. One of the young men who were also persuading her was Surandu, A young man from other village.
Suradu’s attitude in treating arum, made arum fell in love with him. So, there was an affair between them.
Behinde her happiness, Arum felt so sad because she knew that her parents were picking a fiance who she didn’t like at all.
One day, her father called her because there was a purpose of sudden that should be done. “Did you call me father?” ask Arum to his father. “Yes,, Arum, I will go to our neighbouring village with your mother. I want you to take control of the fields as what I’ve taught the last day about how to control our fields. Do you mind?” asked her father
“No, but what time you will go home, father?” Arum asked. “If the business has done, we will go home as soon as possible.” The father replied.
“Alright, father, I hope it could be done as soon as possible”. Arum said to his father.
After packing some stuff, her parents said goodbye to her. “Take care of yourself, Arum. If your activity has done, you should go home as soon as possible”. Her mother gave her a message.
“Yes, mother”. Arum answered.
They went to the neighbouring village on foot with Arum who walked along with them until at the end of the village road.
After the sun was straigt to his head, Arum went to the fields with her lovely dog that was name Toki. When she had arrived to the fields, she didn’t go to work immediately. Her eyes were glazing. Then she approached to a big rock. It was like a buffalo-size rock.
Arum sat on the rock and mused while looking at Toba Lake with empty eyes. He talks to herself:” mother and father would be in her fiance now. They must be arguing yhe day of the wedding….Oh, god, what should I do..?. My mother and my Father had picked a faire for me who is still my cousin. Meanwhile, I have a boyfriend. I even had promised to have a happy family with him.”
Arum cried, she didn’t know what to do. What should she pick for a way out? The problem that she had been difficult and hurted hurt deeply so that she had forgotten to work on her fields.
She became more confused when Surando said that he and his family would go to her house to purpose her in a few days.
But what a pity, before she told her mother about it, her mother had accepted a purpose from another. Arum would be married by a young man who was still having a family relationship. He was a son from her aunt.
It made Arum felt so down. It had benn days that she couldn’t sleep well. She couldn’t eat well also. She was depressed.
Her mind was in an uprare. She didn’t dare to refuse her parents willingness because she was respecting them. But she couldn’t survive without her love.
Arum felt that she had to make her parents happy by showing them her devotion. In the other hand, she had promised to Surandu to live together forever.
Meanwhile, Toki who sat besides her looked at its master with sad eyes as it felt its master’s feeling.
Arumi became more confused, she was just crying and despiring
Arum got up slowly.She stood up with eyes filled with tears. She walked to Toba Lake and said: “Oh, mother, father and my darling I’m sorry for my powerlessness. ...i felt I can’t live with a life full of trials and obstacles. I can’t make you happy also, mother and father”.
“Maybe death will be the best way for this powerless!”
Arumi was going to end her life; she went to a steep cliff and she wanted to jump to the lake. Toki, the dog had a bad feeling so that he was barking while following his master.
Because of her chaotic feeling, she didn’t look at the pass way carefully so that she slipped into a big stone pit.
Arum was surprised. She shouted loudly. “help…help…!!”
The stone pit was so deep. Nobody knew about the accident. Meanwhile, Toki couldn’t make anything but barking and barking.
Arum had hit the bottom of the piit where there was no light because the sun couldn’t reach the bottom of the hole. Arum could only touch the stone without seeing anything.
She tought it was possible for her to go out. In her despired. She became brave. She even shouted to the stone to moor. “ Parapat….!Parapat batu…parapatlah!!” (Moor! moor…! moor..!)
Arum wanted the stone to tie her up and she would die in the hole without nobody knew that she had been there.
Toki was still barking. It had made an attraction of two farmers who passed the way unintended.
First farmr: “The dog looked like arums, our neighbour”
Second farmer:” you are right, why it is barking continuously?”
First farmer: “We better go there”.
Both of the farmers rushed to toward the dog. They saw a big stone pit. They were surprising by a voice that they were familiar with.
First farmer: “I know this voice. It is arums!”
Second farmer:” Yes, you are right.”
First farmer: “What is she doing down there and why is she shouting: Parapat, parapatlah batu?”
Second farmer: “There is something wrong here. We have to help her”.
First farmer: “but how? The sun is almost set now!”
It was true that the sun had almost set. They felt that they couldn’t help so that the two farmers decided to ask some help from other neighbour. Toki was brought home so that it could be a provement.
At the same time, Arum’s parents who had home were surprise that their daughter were not home yet.They felt something’s wrong. So the father decided to go to the fields.
On the way to the fieds, he met the two farmers.” Did you see my daughter?” he asked. “Yes,she had fallen to the bottom of the rock pit over there, here’s the dog. We were incapable to help her. It was so difficult to help her.” They answered. Without asking more, the father rushed to the stone pit.
The news had spread quickly, people went out from their house to know what had happened. The young men of the village rushed leaving the people behind.
After the people had gathered near my the stone pit, they were trying to help her, but they were confused by the torch that they brought can not light up the stone pit.
People were hearing Arum’s voice who had shouted “ Parapatlah…!parapat Batu….Perapatlah!”
“Aruuuuuuumm…! Arum’s mother shouted desperately. Then her mother fainted. She had helped by their neighbour.
When a rope that they had thrown couldn’t touch the bottom of the stone pit, her father tried to save her daughter himself, but the villagers had prevented it first. They tought it could be dangerous.
Suddenly there was bluster. The rock moved and closed itself so that the people couldn’t save the poor girl.
The father fell down. He was powerless. His face had turned pale. He was so sad because Arumi was her only child and arumi was the most beautiful girl in his village,
The young men who wanted to be his wife was desperate and regreted because tere would any girl as pretty as her.
Days had gone by; a ceremony had been held to commemorate the accident. Many people from other places came to see what had happened. Some of them explained that they heard that arum had shouted to the stone pit to moor her. The girl shouted:”Parapatlah…Parapat batu..Parapatlah….!
Because “parapat” words used to be said among villagers, people agreed to memorise it and celebrate a fair which had been named as “Parapatan”.
But, soon there was an earthquake which had made people run everywhere to selfthemselves. Meanwhile, the earth shocking hardly, even harder that the earthquake had destroyed houses, trees and human.
After the earthquake had stopped, a scary view appeared. Many pets and people died. But the most surprising that there was a big stone that appeared suddenly. The stone looked like a girl. The existance was like hanging to the mountain side.
People believe that the hanging rock was the manifestation of a girl who died in the stone. They named the stone as “Batu Gantung” or hanging rock.
Parapatan that was a name of a ceremony became a small city which is located close to Toba Lake. That’s all a history about “Batu Gantung” in north Sumatra. 


 

TOBA LAKE

Lake Toba

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Lake Toba
Landsat photo
Location North Sumatra, Indonesia
Coordinates 2.6845°N 98.8756°ECoordinates: 2.6845°N 98.8756°E
Lake type Volcanic/ tectonic
Primary outflows Asahan River
Basin countries Indonesia

Max. length 100 km (62 mi)
Max. width 30 km (19 mi)
Surface area 1,130 km2 (440 sq mi)
Max. depth 505 m (1,657 ft)[1]
Water volume 240 km3 (58 cu mi)
Surface elevation 905 m (2,969 ft)

Islands Samosir
References [1]
Lake Toba (Indonesian: Danau Toba) is a lake and supervolcano. The lake is 100 kilometres long, 30 kilometres wide, and up to 505 metres (1,666 ft) deep. Located in the middle of the northern part of the Indonesian island of Sumatra with a surface elevation of about 900 metres (2,953 ft), the lake stretches from 2.88°N 98.52°E to 2.35°N 99.1°E. It is the largest lake in Indonesia and the largest volcanic lake in the world.[1]
Lake Toba is the site of a massive supervolcanic eruption estimated at VEI 8 that occurred 69,000 to 77,000 years ago,[2][3][4] representing a climate-changing event. It is the largest known explosive eruption on Earth in the last 25 million years. According to the Toba catastrophe theory, it had global consequences for human populations: it killed most humans living at that time and is believed to have created a population bottleneck in central east Africa and India, which affects the genetic make up of the human world-wide population to the present.[5] This hypothesis is not widely accepted because evidence is lacking for a decline or extinction of other animals, including species that are sensitive to changes in the environment.[6] It has been accepted that the eruption of Toba led to a volcanic winter with a worldwide decrease in temperature between 3 to 5 °C (5 to 9 °F), and up to 15 °C (27 °F) in higher latitudes.

Contents

Geology

The Toba caldera complex in Northern Sumatra, Indonesia, comprises four overlapping volcanic craters that adjoin the Sumatran "volcanic front." The youngest and fourth caldera is the world's largest Quaternary caldera (100 by 30 km (62 by 19 mi)) and intersects the three older calderas. An estimated 2,800 km3 (670 cu mi) of dense-rock equivalent pyroclastic material, known as the youngest Toba tuff, was released during one of the largest explosive volcanic eruptions in recent geologic history. Following this eruption, a resurgent dome formed within the new caldera, joining two half-domes separated by a longitudinal graben.[3]
At least four cones, four stratovolcanoes, and three craters are visible in the lake. The Tandukbenua cone on the north-western edge of the caldera has only sparse vegetation, suggesting a young age of several hundred years. Also, the Pusubukit volcano on the south edge of the caldera is solfatarically active.[7]
Panoramic view of the town of Ambarita on Samosir, Lake Toba
Lake Toba Aerial View
Aerial view of the southern shore with Sibandang Island visible in the background.

The eruption

Location of Lake Toba shown in red on map.
The Toba eruption (the Toba event) occurred at what is now Lake Toba about 67,500 to 75,500 years ago.[8] It was the last in a series of at least three caldera-forming eruptions at this location, with earlier calderas having formed around 700,000 and 840,000 years ago.[9] This last eruption had an estimated VEI 8, making it possibly the largest explosive volcanic eruption within the last 25 million years.
Bill Rose and Craig Chesner of Michigan Technological University have estimated that the total amount of material released in the eruption was about 2,800 km3 (670 cu mi)[10]—about 2,000 km3 (480 cu mi) of ignimbrite that flowed over the ground, and approximately 800 km3 (190 cu mi) that fell as ash mostly to the west. The pyroclastic flows of the eruption destroyed an area of 20,000 km2 (7,722 sq mi), with ash deposits as thick as 600 m (1,969 ft) by the main vent.[10]
The eruption was large enough to have deposited an ash layer approximately 15 cm (5.9 in) thick over all of South Asia; at one site in central India, the Toba ash layer today is up to 6 m (20 ft) thick[11] and parts of Malaysia were covered with 9 m (30 ft) of ash fall.[12] In addition it has been variously calculated that 10,000 million tonnes (1.1×1010 short tons) of sulfuric acid[13][citation needed] or 6,000 million tonnes (6.6×109 short tons) of sulfur dioxide[14] were ejected into the atmosphere by the event.
The subsequent collapse formed a caldera that, after filling with water, created Lake Toba. The island in the center of the lake is formed by a resurgent dome.
Landsat photo of Sumatra surrounding Lake Toba
The exact year of the eruption is unknown, but the pattern of ash deposits suggests that it occurred during the northern summer because only the summer monsoon could have deposited Toba ashfall in the South China Sea.[15] The eruption lasted perhaps two weeks, and the ensuing "volcanic winter" resulted in a decrease in average global temperatures by 3.0 to 3.5 °C (5 to 6 °F) for several years. Greenland ice cores record a pulse of starkly reduced levels of organic carbon sequestration. Very few plants or animals in southeast Asia would have survived, and it is possible that the eruption caused a planet-wide die-off.
Evidence from studies of mitochondrial DNA suggests that humans may have passed through a genetic bottleneck around this time that reduced genetic diversity below what would be expected given the age of the species. According to the Toba catastrophe theory, proposed by Stanley H. Ambrose of the University of Illinois at Urbana-Champaign in 1998, the effects of the Toba eruption may have decreased the size of human populations to only a few tens of thousands of individuals.[16] However, this hypothesis is not widely accepted because similar effects on other animal species have not been observed.[6]

More recent activity

Since the major eruption ~70,000 years ago, eruptions of smaller magnitude have also occurred at Toba. The small cone of Pusukbukit formed on the southwestern margin of the caldera and lava domes. The most recent eruption may have been at Tandukbenua on the northwestern caldera edge, suggested by a lack of vegetation that could be due to an eruption within the last few hundred years.[17]
Some parts of the caldera have shown uplift due to partial refilling of the magma chamber, for example, pushing Samosir Island and the Uluan Peninsula above the surface of the lake. The lake sediments on Samosir Island show that it has raised by at least 450 m (1,476 ft)[9] since the cataclysmic eruption. Such uplifts are common in very large calderas, apparently due to the upward pressure of below-ground magma. Toba is probably the largest resurgent caldera on Earth. Large earthquakes have recently occurred in the vicinity of the volcano, notably in 1987 along the southern shore of the lake at a depth of 11 km (6.8 mi).[18] Such earthquakes have also been recorded in 1892, 1916, and 1920–1922.[9]
Lake Toba lies near the Great Sumatran fault, which runs along the centre of Sumatra in the Sumatra Fracture Zone.[9] The volcanoes of Sumatra and Java are part of the Sunda Arc, a result of the northeasterly movement of the Indo-Australian Plate, which is sliding under the eastward-moving Eurasian Plate. The subduction zone in this area is very active: the seabed near the west coast of Sumatra has had several major earthquakes since 1995, including the 9.1 2004 Indian Ocean Earthquake and the 8.7 2005 Sumatra earthquake, the epicenters of which were around 300 km (190 mi) from Toba.
View of the lake with an example of Batak architecture in the foreground.
Traditional Batak house at Ambarita, Lake Toba

People

Most of the people who live around Lake Toba are ethnically Bataks. Traditional Batak houses are noted for their distinctive roofs (which curve upwards at each end, as a boat's hull does) and their colorful decor.[19]

Flora and fauna

The flora of the lake includes various types of phytoplankton, emerged macrophytes, floating macrophytes, and submerged macrophytes, while the surrounding countryside is rainforest including areas of Sumatran tropical pine forests on the higher mountainsides.[20]
The fauna includes several species of zooplankton and benthic animals. Since the lake is oligotrophic (nutrient-poor), the native fish fauna is relatively scarce, and the only endemics are Rasbora tobana (strictly speaking near-endemic, since also found in some tributary rivers that run into the lake)[21] and Neolissochilus thienemanni, locally known as the Batak fish.[22] The latter species is threatened by deforestation (causing siltation), pollution, changes in water level and the numerous fish species that have been introduced to the lake.[22] Other native fishes include species such as Aplocheilus panchax, Nemacheilus pfeifferae, Homaloptera gymnogaster, Channa gachua, Channa striata, Clarias batrachus, Barbonymus gonionotus, Barbonymus schwanenfeldii, Danio albolineatus, Osteochilus vittatus, Puntius binotatus, Rasbora jacobsoni, Tor tambra, Betta imbellis, Betta taeniata and Monopterus albus.[23] Among the many introduced species are Anabas testudineus, Oreochromis mossambicus, Oreochromis niloticus, Ctenopharyngodon idella, Cyprinus carpio, Osphronemus goramy, Trichogaster pectoralis, Trichopodus trichopterus, Poecilia reticulata and Xiphophorus hellerii.[23]