Oktober 25, 2010

tugas

Posted in Uncategorized pada 6:58 am oleh puji11a329

Landslide

From Wikipedia, the free encyclopedia

Jump to: navigation, search

This article is about the geological phenomenon. For Ruddslide (disambiguation), see Landslide (disambiguation).
“Rockslide” redirects here. For the comic book character, see Rockslide (comics).
This article needs attention from an expert on the subject. See the talk page for details. WikiProject Geology or the Geology Portal may be able to help recruit an expert. (November 2007)
 

Computer simulation of a “slump” landslide in San Mateo County, California (USA) in January 1997

A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rock falls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments. Although the action of gravity is the primary driving force for a landslide to occur, there are other contributing factors affecting the original slope stability. Typically, pre-conditional factors build up specific sub-surface conditions that make the area/slope prone to failure, whereas the actual landslide often requires a trigger before being released.

Contents

[hide]

//

[edit] Causes

Main article: Causes of landslides
 

The Mameyes Landslide, in barrio Tibes, Ponce, Puerto Rico, which buried more than 100 homes, was caused by extensive accumulation of rains and, according to some sources, lightning.

Landslides occur when the stability of a slope changes from a stable to an unstable condition. A change in the stability of a slope can be caused by a number of factors, acting together or alone. Natural causes of landslides include:

landslides are aggravated by human activities, Human causes include:deforestation, cultivation and construction, which destabilize the already fragile slopes

 

The landslide at Surte in Sweden, 1950. It was a quick clay slide killing one person.

[edit] Types

The following text needs to be harmonized with text in Landslide classification.
Main article: Landslide classification

[edit] Debris flow

 

Amboori debris flow, occurred on 9 November 2001 in Kerala, India. The event killed 39 people.[1]

Slope material that becomes saturated with water may develop into a debris flow or mud flow. The resulting slurry of rock and mud may pick up trees, houses and cars, thus blocking bridges and tributaries causing flooding along its path.

Debris flow is often mistaken for flash flood, but they are entirely different processes.

Muddy-debris flows in alpine areas cause severe damage to structures and infrastructure and often claim human lives. Muddy-debris flows can start as a result of slope-related factors and shallow landslides can dam stream beds, resulting in temporary water blockage. As the impoundments fail, a “domino effect” may be created, with a remarkable growth in the volume of the flowing mass, which takes up the debris in the stream channel. The solid-liquid mixture can reach densities of up to 2 tons/m³ and velocities of up to 14 m/s (Chiarle and Luino, 1998; Arattano, 2003). These processes normally cause the first severe road interruptions, due not only to deposits accumulated on the road (from several cubic metres to hundreds of cubic metres), but in some cases to the complete removal of bridges or roadways or railways crossing the stream channel. Damage usually derives from a common underestimation of mud-debris flows: in the alpine valleys, for example, bridges are frequently destroyed by the impact force of the flow because their span is usually calculated only for a water discharge. For a small basin in the Italian Alps (area = 1.76 km²) affected by a debris flow, Chiarle and Luino (1998)[citation needed] estimated a peak discharge of 750 m3/s for a section located in the middle stretch of the main channel. At the same cross section, the maximum foreseeable water discharge (by HEC-1), was 19 m³/s, a value about 40 times lower than that calculated for the debris flow that occurred.

[edit] Earth flow

 

A rock slide in Guerrero, Mexico

Earthflows are downslope, viscous flows of saturated, fine-grained materials, which move at any speed from slow to fast. Typically, they can move at speeds from 0.17 to 20 km/h. Though these are a lot like mudflows, overall they are slower moving and are covered with solid material carried along by flow from within. They are different from fluid flows in that they are more rapid. Clay, fine sand and silt, and fine-grained, pyroclastic material are all susceptible to earthflows. The velocity of the earthflow is all dependent on how much water content is in the flow itself: if there is more water content in the flow, the higher the velocity will be.

These flows usually begin when the pore pressures in a fine-grained mass increase until enough of the weight of the material is supported by pore water to significantly decrease the internal shearing strength of the material. This thereby creates a bulging lobe which advances with a slow, rolling motion. As these lobes spread out, drainage of the mass increases and the margins dry out, thereby lowering the overall velocity of the flow. This process causes the flow to thicken. The bulbous variety of earthflows are not that spectacular, but they are much more common than their rapid counterparts. They develop a sag at their heads and are usually derived from the slumping at the source.

Earthflows occur much more during periods of high precipitation, which saturates the ground and adds water to the slope content. Fissures develop during the movement of clay-like material creates the intrusion of water into the earthflows. Water then increases the pore-water pressure and reduces the shearing strength of the material.[2]

[edit] Debris avalanche

 

Goodell Creek Debris Avalanche, Washington

A debris avalanche is a type of slide characterized by the chaotic movement of rocks soil and debris mixed with water or ice (or both). They are usually triggered by the saturation of thickly vegetated slopes which results in an incoherent mixture of broken timber, smaller vegetation and other debris.[3] Debris avalanches differ from debris slides because their movement is much more rapid. This is usually a result of lower cohesion or higher water content and commonly steeper slopes.

Movement

Debris slides generally begin with large blocks that slump at the head of the slide and then break apart as they move towards the toe. This process is much slower than that of a debris avalanche. In a debris avalanche this progressive failure is very rapid and the entire mass seems to somewhat liquefy as it moves down the slope. This is caused by the combination of the excessive saturation of the material, and very steep slopes. As the mass moves down the slope it generally follows stream channels leaving behind a V-shaped scar that spreads out downhill. This differs from the more U-shaped scar of a slump. Debris avalanches can also travel well past the foot of the slope due to their tremendous speed.[4]

 

Blockade of Hunza river

[edit] Sturzstrom

A sturzstrom is a rare, poorly understood type of landslide, typically with a long run-out. Often very large, these slides are unusually mobile, flowing very far over a low angle, flat, or even slightly uphill terrain.

See also: Slump (geology)

[edit] Shallow landslide

 

Hotel Limone at the Garda Lake. Part of a hill of Devonian shale was removed to make the road, forming a dip-slope. The upper block detached along a bedding plane and is sliding down the hill, forming a jumbled pile of rock at the toe of the slide.

Landslide in which the sliding surface is located within the soil mantle or weathered bedrock (typically to a depth from few decimetres to some metres). They usually include debris slides, debris flow, and failures of road cut-slopes. Landslides occurring as single large blocks of rock moving slowly down slope are sometimes called block glides.

Shallow landslides can often happen in areas that have slopes with high permeable soils on top of low permeable bottom soils. The low permeable, bottom soils trap the water in the shallower, high permeable soils creating high water pressure in the top soils. As the top soils are filled with water and become heavy, slopes can become very unstable and slide over the low permeable bottom soils. Say there is a slope with silt and sand as its top soil and bedrock as its bottom soil. During an intense rainstorm, the bedrock will keep the rain trapped in the top soils of silt and sand. As the topsoil becomes saturated and heavy, it can start to slide over the bedrock and become a shallow landslide. R. H. Campbell did a study on shallow landslides on Santa Cruz Island California. He notes that if permeability decreases with depth, a perched water table may develop in soils at intense precipitation. When pore water pressures are sufficient to reduce effective normal stress to a critical level, failure occurs.[5]

[edit] Deep-seated landslide

 

Landslide of soil and regolith in Pakistan

Landslides in which the sliding surface is mostly deeply located below the maximum rooting depth of trees (typically to depths greater than ten meters). Deep-seated landslides usually involve deep regolith, weathered rock, and/or bedrock and include large slope failure associated with translational, rotational, or complex movement. These typically move slowly, only several meters per year, but occasionally move faster. They tend to be larger than shallow landslides and form along a plane of weakness such as a fault or bedding plane. They can be visually identified by concave scarps at the top and steep areas at the toe.[6]

[edit] Causing tsunamis

Landslides that occur undersea, or have impact into water, can generate tsunamis. Massive landslides can also generate megatsunamis, which are usually hundreds of meters high. In 1958, one such tsunami occurred in Lituya Bay in Alaska.

[edit] Related phenomena

  • An avalanche, similar in mechanism to a landslide, involves a large amount of ice, snow and rock falling quickly down the side of a mountain.
  • A pyroclastic flow is caused by a collapsing cloud of hot ash, gas and rocks from a volcanic explosion that moves rapidly down an erupting volcano.

[edit] Landslide prediction mapping

 

Global landslide risks

 

Ferguson Slide on California State Route 140 in June 2006

Landslide hazard analysis and mapping can provide useful information for catastrophic loss reduction, and assist in the development of guidelines for sustainable land use planning. The analysis is used to identify the factors that are related to landslides, estimate the relative contribution of factors causing slope failures, establish a relation between the factors and landslides, and to predict the landslide hazard in the future based on such a relationship [7]. The factors that have been used for landslide hazard analysis can usually be grouped into geomorphology, geology, land use/land cover, and hydrogeology [8]. Since many factors are considered for landslide hazard mapping, GIS is an appropriate tool because it has functions of collection, storage, manipulation, display, and analysis of large amounts of spatially referenced data which can be handled fast and effectively [9]. Remote sensing techniques are also highly employed for landslide hazard assessment and analysis. Before and after aerial photographs and satellite imagery are used to gather landslide characteristics, like distribution and classification, and factors like slope, lithology, and land use/land cover to be used to help predict future events [10]. Before and after imagery also helps to reveal how the landscape changed after an event, what may have triggered the landslide, and shows the process of regeneration and recovery [11].

Using satellite imagery in combination with GIS and on-the-ground studies, it is possible to generate maps of likely occurrences of future landslides [12]. Such maps should show the locations of previous events as well as clearly indicate the probable locations of future events. In general, to predict landslides, one must assume that their occurrence is determined by certain geologic factors, and that future landslides will occur under the same conditions as past events [13]. Therefore, it is necessary to establish a relationship between the geomorphologic conditions in which the past events took place and the expected future conditions [14].

Natural disasters are a dramatic example of people living in conflict with the environment. Early predictions and warnings are essential for the reduction of property damage and loss of life. Because landslides occur frequently and can represent some of the most destructive forces on earth, it is imperative to have a good understanding as to what causes them and how people can either help prevent them from occurring or simply avoid them when they do occur. Sustainable land management and development is an essential key to reducing the negative impacts felt by landslides.

GIS offers a superior method for landslide analysis because it allows one to capture, store, manipulate, analyze, and display large amounts of data quickly and effectively. Because so many variables are involved, it is important to be able to overlay the many layers of data to develop a full and accurate portrayal of what is taking place on the Earth’s surface. Researchers need to know which variables are the most important factors that trigger landslides in any given location. Using GIS, extremely detailed maps can be generated to show past events and likely future events which have the potential to save lives, property, and money.

[edit] Prehistoric landslides

 

Rhine cutting through Flims Rockslide debris, Switzerland

  • Landslide which moved Heart Mountain to its current location, the largest ever discovered on land. In the 48 million years since the slide occurred, erosion has removed most of the portion of the slide.
  • Flims Rockslide, ca. 13,000 km3 (8.1×109 mi), Switzerland, some 10000 years ago in post-glacial Pleistocene/Holocene, the largest so far described in the alps and on dry land that can be easily identified in a modestly eroded state.[15]
  • The landslide around 200BC which formed Lake Waikaremoana on the North Island of New Zealand, where a large block of the Ngamoko Range slid and dammed a gorge of Waikaretaheke River, forming a natural reservoir up to 248 metres deep.
  • Cheekye Fan, British Columbia, Canada, ca. 25 km2 (9.7 sq mi), Late Pleistocene in age.

[edit] Prehistoric submarine landslides

[edit] Historical landslides

[edit] 19th Century

[edit] 20th Century

[edit] 21st Century

tugas

Posted in Uncategorized pada 6:54 am oleh puji11a329

Landslide

From Wikipedia, the free encyclopedia

Jump to: navigation, search

This article is about the geological phenomenon. For Ruddslide (disambiguation), see Landslide (disambiguation).
“Rockslide” redirects here. For the comic book character, see Rockslide (comics).
This article needs attention from an expert on the subject. See the talk page for details. WikiProject Geology or the Geology Portal may be able to help recruit an expert. (November 2007)

Computer simulation of a “slump” landslide in San Mateo County, California (USA) in January 1997

A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rock falls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments. Although the action of gravity is the primary driving force for a landslide to occur, there are other contributing factors affecting the original slope stability. Typically, pre-conditional factors build up specific sub-surface conditions that make the area/slope prone to failure, whereas the actual landslide often requires a trigger before being released.

Contents

[hide]

//

[edit] Causes

Main article: Causes of landslides

The Mameyes Landslide, in barrio Tibes, Ponce, Puerto Rico, which buried more than 100 homes, was caused by extensive accumulation of rains and, according to some sources, lightning.

Landslides occur when the stability of a slope changes from a stable to an unstable condition. A change in the stability of a slope can be caused by a number of factors, acting together or alone. Natural causes of landslides include:

landslides are aggravated by human activities, Human causes include:deforestation, cultivation and construction, which destabilize the already fragile slopes

The landslide at Surte in Sweden, 1950. It was a quick clay slide killing one person.

[edit] Types

The following text needs to be harmonized with text in Landslide classification.
Main article: Landslide classification

[edit] Debris flow

Amboori debris flow, occurred on 9 November 2001 in Kerala, India. The event killed 39 people.[1]

Slope material that becomes saturated with water may develop into a debris flow or mud flow. The resulting slurry of rock and mud may pick up trees, houses and cars, thus blocking bridges and tributaries causing flooding along its path.

Debris flow is often mistaken for flash flood, but they are entirely different processes.

Muddy-debris flows in alpine areas cause severe damage to structures and infrastructure and often claim human lives. Muddy-debris flows can start as a result of slope-related factors and shallow landslides can dam stream beds, resulting in temporary water blockage. As the impoundments fail, a “domino effect” may be created, with a remarkable growth in the volume of the flowing mass, which takes up the debris in the stream channel. The solid-liquid mixture can reach densities of up to 2 tons/m³ and velocities of up to 14 m/s (Chiarle and Luino, 1998; Arattano, 2003). These processes normally cause the first severe road interruptions, due not only to deposits accumulated on the road (from several cubic metres to hundreds of cubic metres), but in some cases to the complete removal of bridges or roadways or railways crossing the stream channel. Damage usually derives from a common underestimation of mud-debris flows: in the alpine valleys, for example, bridges are frequently destroyed by the impact force of the flow because their span is usually calculated only for a water discharge. For a small basin in the Italian Alps (area = 1.76 km²) affected by a debris flow, Chiarle and Luino (1998)[citation needed] estimated a peak discharge of 750 m3/s for a section located in the middle stretch of the main channel. At the same cross section, the maximum foreseeable water discharge (by HEC-1), was 19 m³/s, a value about 40 times lower than that calculated for the debris flow that occurred.

[edit] Earth flow

A rock slide in Guerrero, Mexico

Earthflows are downslope, viscous flows of saturated, fine-grained materials, which move at any speed from slow to fast. Typically, they can move at speeds from 0.17 to 20 km/h. Though these are a lot like mudflows, overall they are slower moving and are covered with solid material carried along by flow from within. They are different from fluid flows in that they are more rapid. Clay, fine sand and silt, and fine-grained, pyroclastic material are all susceptible to earthflows. The velocity of the earthflow is all dependent on how much water content is in the flow itself: if there is more water content in the flow, the higher the velocity will be.

These flows usually begin when the pore pressures in a fine-grained mass increase until enough of the weight of the material is supported by pore water to significantly decrease the internal shearing strength of the material. This thereby creates a bulging lobe which advances with a slow, rolling motion. As these lobes spread out, drainage of the mass increases and the margins dry out, thereby lowering the overall velocity of the flow. This process causes the flow to thicken. The bulbous variety of earthflows are not that spectacular, but they are much more common than their rapid counterparts. They develop a sag at their heads and are usually derived from the slumping at the source.

Earthflows occur much more during periods of high precipitation, which saturates the ground and adds water to the slope content. Fissures develop during the movement of clay-like material creates the intrusion of water into the earthflows. Water then increases the pore-water pressure and reduces the shearing strength of the material.[2]

[edit] Debris avalanche

Goodell Creek Debris Avalanche, Washington

A debris avalanche is a type of slide characterized by the chaotic movement of rocks soil and debris mixed with water or ice (or both). They are usually triggered by the saturation of thickly vegetated slopes which results in an incoherent mixture of broken timber, smaller vegetation and other debris.[3] Debris avalanches differ from debris slides because their movement is much more rapid. This is usually a result of lower cohesion or higher water content and commonly steeper slopes.

Movement

Debris slides generally begin with large blocks that slump at the head of the slide and then break apart as they move towards the toe. This process is much slower than that of a debris avalanche. In a debris avalanche this progressive failure is very rapid and the entire mass seems to somewhat liquefy as it moves down the slope. This is caused by the combination of the excessive saturation of the material, and very steep slopes. As the mass moves down the slope it generally follows stream channels leaving behind a V-shaped scar that spreads out downhill. This differs from the more U-shaped scar of a slump. Debris avalanches can also travel well past the foot of the slope due to their tremendous speed.[4]

Blockade of Hunza river

[edit] Sturzstrom

A sturzstrom is a rare, poorly understood type of landslide, typically with a long run-out. Often very large, these slides are unusually mobile, flowing very far over a low angle, flat, or even slightly uphill terrain.

See also: Slump (geology)

[edit] Shallow landslide

Hotel Limone at the Garda Lake. Part of a hill of Devonian shale was removed to make the road, forming a dip-slope. The upper block detached along a bedding plane and is sliding down the hill, forming a jumbled pile of rock at the toe of the slide.

Landslide in which the sliding surface is located within the soil mantle or weathered bedrock (typically to a depth from few decimetres to some metres). They usually include debris slides, debris flow, and failures of road cut-slopes. Landslides occurring as single large blocks of rock moving slowly down slope are sometimes called block glides.

Shallow landslides can often happen in areas that have slopes with high permeable soils on top of low permeable bottom soils. The low permeable, bottom soils trap the water in the shallower, high permeable soils creating high water pressure in the top soils. As the top soils are filled with water and become heavy, slopes can become very unstable and slide over the low permeable bottom soils. Say there is a slope with silt and sand as its top soil and bedrock as its bottom soil. During an intense rainstorm, the bedrock will keep the rain trapped in the top soils of silt and sand. As the topsoil becomes saturated and heavy, it can start to slide over the bedrock and become a shallow landslide. R. H. Campbell did a study on shallow landslides on Santa Cruz Island California. He notes that if permeability decreases with depth, a perched water table may develop in soils at intense precipitation. When pore water pressures are sufficient to reduce effective normal stress to a critical level, failure occurs.[5]

[edit] Deep-seated landslide

Landslide of soil and regolith in Pakistan

Landslides in which the sliding surface is mostly deeply located below the maximum rooting depth of trees (typically to depths greater than ten meters). Deep-seated landslides usually involve deep regolith, weathered rock, and/or bedrock and include large slope failure associated with translational, rotational, or complex movement. These typically move slowly, only several meters per year, but occasionally move faster. They tend to be larger than shallow landslides and form along a plane of weakness such as a fault or bedding plane. They can be visually identified by concave scarps at the top and steep areas at the toe.[6]

[edit] Causing tsunamis

Landslides that occur undersea, or have impact into water, can generate tsunamis. Massive landslides can also generate megatsunamis, which are usually hundreds of meters high. In 1958, one such tsunami occurred in Lituya Bay in Alaska.

[edit] Related phenomena

  • An avalanche, similar in mechanism to a landslide, involves a large amount of ice, snow and rock falling quickly down the side of a mountain.
  • A pyroclastic flow is caused by a collapsing cloud of hot ash, gas and rocks from a volcanic explosion that moves rapidly down an erupting volcano.

[edit] Landslide prediction mapping

Global landslide risks

Ferguson Slide on California State Route 140 in June 2006

Landslide hazard analysis and mapping can provide useful information for catastrophic loss reduction, and assist in the development of guidelines for sustainable land use planning. The analysis is used to identify the factors that are related to landslides, estimate the relative contribution of factors causing slope failures, establish a relation between the factors and landslides, and to predict the landslide hazard in the future based on such a relationship [7]. The factors that have been used for landslide hazard analysis can usually be grouped into geomorphology, geology, land use/land cover, and hydrogeology [8]. Since many factors are considered for landslide hazard mapping, GIS is an appropriate tool because it has functions of collection, storage, manipulation, display, and analysis of large amounts of spatially referenced data which can be handled fast and effectively [9]. Remote sensing techniques are also highly employed for landslide hazard assessment and analysis. Before and after aerial photographs and satellite imagery are used to gather landslide characteristics, like distribution and classification, and factors like slope, lithology, and land use/land cover to be used to help predict future events [10]. Before and after imagery also helps to reveal how the landscape changed after an event, what may have triggered the landslide, and shows the process of regeneration and recovery [11].

Using satellite imagery in combination with GIS and on-the-ground studies, it is possible to generate maps of likely occurrences of future landslides [12]. Such maps should show the locations of previous events as well as clearly indicate the probable locations of future events. In general, to predict landslides, one must assume that their occurrence is determined by certain geologic factors, and that future landslides will occur under the same conditions as past events [13]. Therefore, it is necessary to establish a relationship between the geomorphologic conditions in which the past events took place and the expected future conditions [14].

Natural disasters are a dramatic example of people living in conflict with the environment. Early predictions and warnings are essential for the reduction of property damage and loss of life. Because landslides occur frequently and can represent some of the most destructive forces on earth, it is imperative to have a good understanding as to what causes them and how people can either help prevent them from occurring or simply avoid them when they do occur. Sustainable land management and development is an essential key to reducing the negative impacts felt by landslides.

GIS offers a superior method for landslide analysis because it allows one to capture, store, manipulate, analyze, and display large amounts of data quickly and effectively. Because so many variables are involved, it is important to be able to overlay the many layers of data to develop a full and accurate portrayal of what is taking place on the Earth’s surface. Researchers need to know which variables are the most important factors that trigger landslides in any given location. Using GIS, extremely detailed maps can be generated to show past events and likely future events which have the potential to save lives, property, and money.

[edit] Prehistoric landslides

Rhine cutting through Flims Rockslide debris, Switzerland

  • Landslide which moved Heart Mountain to its current location, the largest ever discovered on land. In the 48 million years since the slide occurred, erosion has removed most of the portion of the slide.
  • Flims Rockslide, ca. 13,000 km3 (8.1×109 mi), Switzerland, some 10000 years ago in post-glacial Pleistocene/Holocene, the largest so far described in the alps and on dry land that can be easily identified in a modestly eroded state.[15]
  • The landslide around 200BC which formed Lake Waikaremoana on the North Island of New Zealand, where a large block of the Ngamoko Range slid and dammed a gorge of Waikaretaheke River, forming a natural reservoir up to 248 metres deep.
  • Cheekye Fan, British Columbia, Canada, ca. 25 km2 (9.7 sq mi), Late Pleistocene in age.

[edit] Prehistoric submarine landslides

[edit] Historical landslides

[edit] 19th Century

[edit] 20th Century

[edit] 21st Century

November 11, 2009

Tips sederhana membuat belajar lebih EFEKTIF

Posted in Uncategorized pada 8:08 am oleh puji11a329

1.Seorang teman dari Amerika memberi saran belajar yang dia dapat dari ayahnya. Hari pertama sekolah, ulang kembali pelajaran yang telah didapat. Setelah itu baca singkat dua halaman materi berikutnya buat cari kerangkanya saja. Begitu pelajaran tersebut diterangkan guru esoknya, kamu sudah punya gambaran atau dasarnya, tinggal menambahkan saja apa yang belum kamu tahu. Jadi begitu pulang sekolah, kamu hanya mengulang saja untuk mencari kesimpulan atau ringkasan.2.Usahakan selalu konsentrasi penuh waktu mendengarkan pelajaran di sekolah. Materi yang kamu dengar bakal mudah dipanggil lagi begitu kamu menghapal ulang pelajaran.3.Beberapa temanmu merekomendasikan untuk mengetik ulang catatan pelajaran ke dalam komputer. Logikanya, dengan mengetik ulang catatan berarti sama saja dengan membaca ulang pelajaran yang baru saja kamu dapat dari sekolah. Materi yang diulang tadi bisa tersimpan di memori otak buat jangka waktu yang lama. Lebih bagus lagi kalo kamu mau membaca kembali atau mempelajari catatan tersebut setelah diketik. Susah lupanya!

4.Cara lain adalah dengan membaca ulang catatan pelajaran kemudian buat kesimpulan dengan kata-katamu sendiri. Supaya dapat terpatri lama di memori, tulis kesimpulan kamu tadi di secarik kertas kecil seukuran kartu nama. Kartu-kartu tersebut efektif untuk mengulang dan membaca singkat kala senggang.

5.Teman lainnya menyarankan untuk selalu menggunakan buku catatan yang berbeda pada setiap mata pelajaran. Cara ini dinilai lebih teratur sehingga pada waktu ingin mengulang suatu pelajaran kita tidak perlu lagi harus membuka semua buku.

6.Mengulang pelajaran tidak selamanya harus dengan membaca atau menulis. Mengajari teman lain tentang materi yang baru diulang bisa membuatmu selalu ingat akan materi tersebut. Bagusnya lagi, kamu menjadi lebih paham akan materi tersebut.

7.Belajar mendadak menjelang tes memang tidak efektif. Paling nggak sebulan sebelum ulangan adalah masa ideal buat mengulang pelajaran. Materi yang banyak bukan masalah. Caranya : selalu buat ringkasan atau kesimpulan pada setiap pelajaran, kalau perlu pakai tabel atau gambar ilustrasi supaya mudah diingat.

8.Ada beberapa temanmu di Australia yang menyukai waktu belajar di siang hari. Maklum, badan masih segar setelah tidur cukup di malam hari, jadi semangat masih tinggi. Kondisi yang bagus tersebut tidak mereka sia-siakan begitu saja. Pagi mereka konsentrasi penuh pada pelajaran di kelas dan siangnya konsentrasi untuk mengulang kembali. Malam hari hanya mereka gunakan untuk mengerjakan aktifitas ringan atau pekerjaan rumah. Jadi tidak pernah ada kata begadang. Boleh juga tuh!

9.Kalau badan capek, bakal susah buat konsentrasinya. Beberapa temanmu menyarankan untuk libur dulu dari acara olah raga atau kegiatan fisik lainnya sehari menjelang ulangan umum.

Apa tips tips belajar yang baik dan benar..?!?

Well.. Gw ada beberapa tips buat masalah kayak gini:
1. Mulailah dari yang “kecil”
Mulailah belajar dari topik yang paling anda kuasai / gampang..
Setelah itu barulah dilanjutkan dengan topik yang lebih “menantang”..
Hal ini dimaksudkan agar kita tidak langsung down dan putus asa jika mengerjakan soal2 sulit terlebih dahulu..

2. Sering-seringlah “practice”
Latihan dan latihan itulah kunci untuk mahir dalam suatu mata pelajaran..
Semakin banyak anda mengerjakan dan memahami soal semakin terbiasa pula anda dalam mengerjakannya..

3. Fokus
Ketika belajar, kita dituntut untuk serius..
Jangan setengah hati..
Karena pikiran kita tidak dapat melakukan / memikirkan beberapa kegiatan / hal dalam satu waktu..

4. Malu bertanya sesat di jalan
Jika anda menemukan masalah dalam belajar, jangan malu untuk bertanya pada orang2 sekitar anda..
Dapat berupa guru, teman, orang tua, kakak, dll (yang pasti orang2 yang mampu membantu anda, jangan malah “menyesatkan” anda dengan jawaban yang asal2an)

5. Mohon bimbingan-NYA
Jangan lupa banyak2 berdoa..
Karena selain dari nilai religi-nya, hal tersebut dapat membuat kita lebih fokus ketika belajar dan dapat membuat pikiran kita lebih tenang..

Trus masalah yang paling sulit adalah semangat untuk belajar..
Dan kebetulan gw juga ada beberapa “jurus” yang terbukti “jitu” (bagi gw dan kebanyakan orang yang telah mengaplikasikannya) untuk menciptakan suatu suasana fun ketika belajar dan agar tidak cepat suntuk:
1. Lengkapilah materi pelajaran anda / buku catatan anda dengan gambar-gambar jangan hanya sekedar tulisan.

2. Hiasilah materi pelajaran anda / buku catatan anda dengan menggunakan tinta yang beraneka ragam (bukan hanya satu / dua warna) karena hal tersebut mampu mempengaruhi sistem otak kita, dan menciptakan suatu suasana menarik / semangat ketika membacanya.

3. Membuat catatan kecil.
Nb: Dapat saja berupa fakta-fakta unik seputar hal-hal yang sedang kita pelajari

4. Membuat trik sendiri / Menyisipkan trik untuk memudahkan anda dalam belajar.
Mis: dalam menghafal zat yg terdapat dalam lambung >> “Aku PEREk MUda”
1. Asam Klorida (HCl)
2. PEpsin
3. REnin
4. MUcin
Nb: trik yang dibuat boleh saja agak “lucu / berbau negatif” karena kita akan lebih mudah mengingat hal-hal yang bersifat lucu / “nakal”

5. Belajar dengan menggunakan fasilitas-fasilitas yg menarik seperti computer / lebih spesifiknya internet
Salah satu contohnya itu adalah Y!A. Anda dapat belajar dengan menjawab pertanyaan orang lain (tentunya untuk menjawab anda harus bolak-balik buku / search google maka dari hal tsb anda akan belajar sesuatu yang baru dan secara tidak sengaja minat anda untuk mempelajari hal-hal baru akan terpacu dan mampu menjadi modal anda untuk melajar dengan gembiria).

6. Belajar kelompok. Dalam sebagian kasus murid2 malas belajar karena mereka hanya sendiri namun dengan adanya teman-teman anda akan menjadi terpacu untuk saling berkompetensi menyelesaikan soal serta ada teman yg dapat membantu anda apabila anda kesulitan untuk mengerti suatu soal.

7. Anda harus punya tekad yg kuat.
(asal ada niat semua pasti bisa… ^^)

Semoga bermanfaat.. ^^

4 kejadian aneh di dunia

Posted in Uncategorized pada 7:21 am oleh puji11a329


Di dunia ini banyak sekali terjadi berbagai fenomena unik yang terkadang sangat sulit dijelaskan oleh logika, bahkan sampai sekarang juga banyak sekali kejadian yang tidak bisa dijelaskan oleh logika. Diantara kejadian tersbut, terdapat empat kejadian, yang direkam di dunia modern (setidaknya sampai pada tahun 1518), dan semua kejadian ini sama sekali tidak dapat dijelaskan oleh logika.

1. Kematian Akibat Menari

Juli 1518, seorang wanita yang disebut bernama Frau Troffea berjalan di salah satu jalan sempit di Strasbourg, Prancis, dan mulai menarikan tarian yang berlangsung sekitar empat atau enam hari berturut-turut. Di akhir minggu, 34 orang ikut serta dengan tariannya, dan dalam sebulan, peserta tarian aneh bin ajaib ini mencapai 400 orang.

Para pejabat menyarankan untuk “menari lebih sering” untuk menyembuhkan para penari, tapi pada akhir musim panas, lusian orang di kota Alsatian meninggal karena serangan jantung, stroke, kelelahan karena tarian yang tidak berhenti sama sekali. Selama beberapa abad, kejadian aneh yang disebut sebagai wabah menari atau Epidemi 1518, sama sekali tidak dapat dijelaskan oleh berbagai ilmuwan mengenai apa yang menyebabkan terjadinya tarian kematian yang aneh dan ajaib ini.

2. Wabah Tawa Tanganyika

Mungkin kejadian paling aneh yang berhasil di dokumentasikan dalam penyakit psikogenik massal ini adalah Wabah Tawa Tanganyika pada 1962. Kejadian lengkap atas kondisi ini digambarkan dalam paper yang diterbitkan pada Central African Journal of Medicine yang diterbitkan pada 1963. Wabah ini dimulai dengan adanya becandaan antara para mahasiswa di salah satu asrama di Tanzania, dan dari hal itu, seorang remaja putri mulai tertawa tanpa kendali. Pertama hanya ada sedikit tawa, yang kemudian makin lama makin panjang, dari sekedar jam, sampai berhari-hari.

Korban wabah ini, yang hampir semuanya adalah wanita, akhirnya mengalami kesakitan, pingsan, masalah pernapasan, gatal-gatal dan bahkan menangis, yang semuanya muncul akibat tawa histeris. Bahkan wabah tawa ini menular ke orang tua para mahasiswa, juga sampai ke sekolah lain dan bahkan ke desa sekitarnya. Dibutuhkan waktu 18 bulan lamanya sebelum wabah tertawa ini berhenti total.

3. Hujan Binatang

Kejadian unik ini mungkin adalah kejadian paling banyak ditemui di dunia. Hujan burung, kelelawar, ikan, bahkan cacing dan berudu sudah dilaporkan dari beberapa penjuru dunia. Para ilmuwan melaporkan bahwa kemungkinan besar ada badai dengan kecepatan tinggi dan angin puting beliung yang melewati air, dan menyedot hewan ini, kemudian dijatuhkan di tempat yang jauh. Hampir selama satu abad ini, para penduduk Honduras selama hampir sabad ini merayakan apa yang disebut Lluvia de Peces (Hujan Ikan) setiap tahunnya. Ikan ini dipercaya disedot dari laut dan dijatuhkan 140 mil ke daratan atau mungkin ikan tersebut disedot dari semacam sumber air bawah tahan.

4. Sungai Paling Terpolusi di India tiba-tiba menjadi ‘manis’

2006, Air laut yang masuk ke Mumbai, tiba-tiba berubah rasa menjadi manis, dan fenomena ini di’temukan’ oleh beberapa penduduku Mumbai yang tiba-tiba merasakan air di Sungai Mahim Creek, salah satu sungai paling terpolusi di India, yang menerima ribuan ton limbah mentah dan limbah industri setiap hari-nya tiba-tiba menjadi manis. Selama beberapa jam, penduduk Gujarat mengatakan bahwa air laut di pantai Teethal juga berubah manis.

Dewan Pengendali Polusi Maharashtra (The Maharashtra Pollution Control Board) telah mengeluarkan peringatan agar tidak ada penduduk yang meninum air yang ada, tapi tetap saja banyak orang mengumpulkan air tersebut dalam botol-botol, walaupun banyak sampah dan plastik yang ikut terhanyut dalam arus yang ada. Sekitar jam 2 pagi keesokan harinya, para penduduk yang berjaga mulai mengakui bahwa air yang tadinya manis berubah asin kembali.

Oktober 9, 2009

Pengalaman puasa 1430 H

Posted in Uncategorized pada 4:52 am oleh puji11a329

Bln puasa th ni saya merasa krg senang krn sy hrs melaksanakan semua kegiatan sendiri tanpa ada bantuan. . .selain itu stp plg sekolah hrs naik bus+jln kaki krg lbh 2 Km. . .tp sy jg senang krn Allah msh m’pertemukan sy dg bln ramadhan . . . . . . .saat lebaran tiba, akhirnya semua keluarga bs b’kumpul dan slg memaafkan 1 sama lainnya…..

Gempa di padang,Pariaman

Posted in Uncategorized pada 3:21 am oleh puji11a329

30 sept 09 gempa 7,6 SR guncang solok, sumbar pkl 17.16 dg kedlman laut 71 Km di 57 Km baratdaya pariaman.gempa tsb mengakibatkan 7 gedung di jambi retak,kebakaran dan jaringan telepon rumah dan genggam terputus. selain itu juga mengakibatkan ratusan rumah rata dengan tanah. Ribuan warga mengungsi ditenda2 darurat dan sebagian lari ke bukit.Gempa tsb juga dirasakan didaerah padang , bengkulu , aceh, bandar lampung hingga ke negara tetangga spt Malaysia dan Singapura.

Pemadaman Masih Terjadi, PLN Minta Maaf  

Dialog SCTV dengan Sekretaris PT PLN Persero, Supriyanto (kanan).
, Jakarta: Perusahaan Listrik Negara (PLN) meminta maaf kepada masyarakat atas pemadaman listrik bergilir yang hingga kini masih terjadi. “Kami mohon maaf. Itu karena ada kerusakan peralatan yang tidak bisa dihindari,” kata Sekretaris PT PLN Persero, Supriyanto, dalam perbincangannya dengan reporter SCTV, David Silahooij, Sabtu (14/11).Supriyanto menambahkan, gangguan terutama terjadi di Gardu Cawang, Jakarta Timur dan Gardu Kembangan di Jakarta Barat. Saat ini, kata dia, perbaikan masih terus dilakukan bahkan dipercepat. Semula perbaikan ditargetkan enam bulan, tapi kini jadi tiga bulan. Bahkan akan diupayakan selesai pada pertengahan Desember mendatang. “Kalau maju, kita majukan. Mudah-mudahan tidak terganggu cuaca,” kata Supriyanto

Menurut Supriyanto, sejauh ini kendala yang dihadapi adalah masalah peralatan yang harus didatangkan dari luar negeri. Salah satu komponennya harus didatangkan dari Prancis.

Di luar persoalan tersebut, pasokan listrik untuk Jawa dan Bali masih cukup. Apalagi saat ini pembangunan pembangkit listrik 10 ribu megawatt tengah berjalan, seperti di Labuan dan Rembang. Simak selengkapnya perbincangan David Silahooij dengan Sekretaris PT PLN Persero di video berita ini.(IAN)

Matahari Masih Malas-malasan, ‘Kiamat’ Mundur Tahun 2013


Matahari Masih Malas-malasan, ‘Kiamat’ Mundur Tahun 2013

Tanpa mempedulikan ramalan tentang datangnya kiamat pada tahun 2012, para ilmuwan awalnya sepakat bahwa pada tahun tersebut memang bakalan terjadi badai matahari. Namun, perkiraan itu belakangan bergeser, karena bintik hitam matahari sampai sekarang belum muncul.

Bintik hitam atau secara ilmiah dinamai sunspot adalah tanda-tanda adanya aktivitas matahari. Banyaknya sunspot yang mengandung medan magnet akan menciptakan ledakan sehingga aktivitas matahari dianggap telah mencapai puncaknya. Radiasi gelombang elektromagnetik yang disemburkan oleh ledakan itu dapat mencapai bumi yang berjarak 150 juta Km dari matahari.

Sesuai siklus 11 tahunan matahari, puncak aktivitas matahari akan sampai pada siklus ke-24 pada 2012 nanti. Karena itu, para ilmuwan memperkirakan sunspot akan mulai muncul pada 2007 lalu dan bertambah banyak pada tahun-tahun sesudahnya.

“Tapi ternyata sebagian peneliti melihat sekarang ini belum muncul bintik hitamnya itu,” kata Sri Kaloka Prabotosari, Kepala Pusat Pemanfaatan Sains Antariksa (Pusfatsainsa) Lembaga Penerbangan dan Antariksa Nasional (Lapan) di kantor Lapan Bandung, Jl Djundjunan, Bandung, Jawa Barat, Kamis (10/12/2009).

Kepala Bidang Matahari dan Antariksa Lapan Clara Y Yatini mengatakan, sunspot terbentuk akibat kuatnya medan magnet di permukaan matahari. Tampak gelap yang telihat pada bintik hitam matahari disebabkan karena energi yang ada di sunspot itu tidak bisa dilepaskan.

Dia melanjutkan, karena kuatnya medan magnet pula, badai matahari akan berhembus dari daerah sunspot tersebut. Makin banyak bintik-bintik hitam di matahari, makin besar pula potensi terjadinya badai matahari.

“Itu proses yang terjadi di matahari dan tidak bisa dikontrol. Kalau memang waktunya meledak, ya, meledak,” kata dia.

Senada dengan Sri Kalola, menurut Clara, siklus aktivitas matahari yang ke-24 semula diperkirakan lebih besar dibanding siklus sebelumnya. Akan tetapi, dengan melihat belum adanya sunspot di permukaan matahari, prediksi itu berubah.

Menurutnya, dengan melihat perilaku matahari yang seperti itu, Lapan memprediksi aktivitas matahari akan mencapai puncaknya bukan pada 2012, melainkan Mei 2013. Saat itu, ledakan-ledakan matahari, yang dikait-kaitkan orang dengan ramalan kehancuran bumi dan kiamat, akan terjadi.

“Dengan mengamati matahari terus menerus, kelihatannya matahari ini masih malas-malasan. Akhirnya para peneliti mengulang lagi prediksinya dan mengatakan siklus ke-24 ini bakalan rendah daripada siklus ke-23,” tuturnya.

Oktober 8, 2009

Ca utk cegah osteoporosis

Posted in Uncategorized pada 7:48 am oleh puji11a329

Osteoporosis merup. keadaan dimana masa tulang brkurang dan menjadi rapuh. Gejalanya dapat berupa rassa nyeri kelainan benntuk tulang tinggi badan tidak tumbuh maks, dan retak tulang. pd kondiiai trrsebut komposisi tulg tdk berubah ttp bert tulang/unit volum berkurang pd stadium lnjut mudah mengalami patah tulang terutama pd bag. tangan, pinggang dan tulang bekakang.

September 4, 2009

Hello world!

Posted in Uncategorized pada 3:04 am oleh puji11a329

Welcome to WordPress.com. This is your first post. Edit or delete it and start blogging!