بنابراين يكي از مسائلي كه پزشكان با آن روبه رو هستند  تشخيص صحيح بيماري هاي ناشي از آلودگي هاي معادن در معدنچيان مي باشد كه اين تشخيص نه تنها به درمان و در صورت نياز ، جبران خسارت بيماران مربوطه كمك مي كند بلكه هشداري است به مقامات بهداشتي براي پيشگيري از بروز بيماري هاي مشابه در بيماراني كه در تماس با همان ماده قرار دارند. جدول ذيل اشاره به نام وعامل بيماري ها و نوع معدن و كارگاه معدني دارد كه به صورت مختصر ارائه شده است :

گاز طبیعی بعد از نفت و زغال‌سنگ مهمترین تامین کنندة انرژی جهان محسوب می‎‎شود که به ویژه در سالهای 1980 تا 1990 بعلت داشتن آلودگی زیست محیطی کمتر، کشورهای پیشرفته و در حال توسعه توجه شایانی به مصرف آن از لحاظ تولید برق یا مصرف حرارتی داشته و دارند. تا سال 1985 کشور شوروی سابق صادرکنندة اصلی گاز طبیعی جهان محسوب میشد ولی امروزه کشورهای دیگر ازجمله ایران نیز مبادرت به صدور گاز کرده‎اند. گرچه باید توجه کرد که گاز نیز مثل دیگر انرژی‌های فسیلی پایان‌پذیر می‎باشد.

 انرژی هسته ‎ای در آغاز دهه 1970 مورد بهره‎برداری قرار گرفت تا سال 1985 رشد مصرف آن قابل ملاحظه بود. ولی بعلت پیچیدگی تکنولوژی و وجود مشکلات فراوان در دفع زایدات آن هنوز مثل انرژی‌های دیگر متداول نبوده و سهم چندانی در تامین انرژی جهانی ندارد. می‎توان گفت علت اساسی توقف رشد کاربرد انرژی هسته‎ای سیاست همگانی نشدن روش تغلیظ مواد رادیواکتیو می‎باشد. بعبارت دیگر سیاستهای اقتصادی خارجی سد راه بهره‎گیری همگانی این انرژی در جهان است.

انرژی‌های نو مثل خورشیدی، باد، امواج، بیوماس و غیره هنوز نتوانسته‌اند توسعه و رشد قابل ملاحظه‌ای داشته باشند و تنها می‌توانند تا حد ناچیزی مصرف انرژی فسیلی را کاهش دهند.

 انرژی زمین‌گرمایی تنها انرژی تجدیدپذیر است که بعد از انرژی آبی آلودگی محیط زیست آن بمراتب کمتر از انرژی‌های دیگر است. بیشتر کشورها که در مدار حرکت پهنه‌ها (زمین ساخت پهنه‎ای) قرار گرفته‎اند از انرژی زمین گرمای بطور غیر مستقیم برای تولید الکتریسیته استفاده می‎کنند. براساس آمار جهانی در سال 2000 ظرفیت نصب شده نیروگاه‌های  زمین‌گرمایی بالغ بر 7974 مگاوات الکتریکی است. با توجه به اطلاعات موجود، رشد ظرفیت نیروگاه‌های   زمین‌گرمایی نصب شده در سال 1995 در حدود 28 برابر ظرفیت همین نیروگاهها در سال 1950 میباشد. این موضوع نمایانگر رشد سریع کاربرد الکتریکی انرژی زمین‌گرمایی در جهان است. کشورهای زیادی در موقعیت استفاده از انرژی زمین‌گرمایی قرار گرفته‌اند اما هنوز اقدام به بهره‎گیری از این انرژی نکرده‎اند. چنانکه پیش بینی می‎شود درسالهای آینده با کاهش منابع سوخت فسیلی و با بالارفتن بهای نفت اکثر کشورهایی که در مدار جهانی انرژی زمین‌گرمایی واقع شده‎اند اقدام سریع به بهره‎گیری از این انرژی نمایند که در این صورت استفاده از انرژی زمین‌گرمایی رشد شایانی خواهد داشت.

 در این بخش به بررسی موارد ذیل خواهیم پرداخت که انشالله به صورت عنوانهای جداگانه ارائه خواهند شد:

 1-      روند سرمایه‎گذاری در توسعه منابع زمین‌گرمایی

 2-      دیدگاههای اقتصادی در ارزیابی پروژه‎های زمین گرمایی

3-      روند رشد تولید برق از انرژی زمین‌گرمایی

 4-      عوامل موثر در توسعه صنعت زمین‌گرمایی

5-      هزینه‌های زیست محیطی و تاثیر آن بر توسعه انرژی زمین گرمایی

منبع: فتوحی منوچهر و نوراللهی یونس، ۱۳۸۰، اصول و مبانی انرژی زمین گرمایی، انتشارات میعاد ، تهران، ص ۱۴۸

تهیه کننده : حسین نوروزی

Mount Sabalan

This mountain is a point type volcano bearing

stratovolcano cone.  Its height is 4800m from sea

level located in the western part of Ardebil.  This

mount includes three cones along with each other. 

Lava vast distribution (area of about 1300sq.km)

indicates huge explosion and discharge of lava high

volume.  

Sabalan region is located on the Oligocene big horst,

geologically.  Its activity commenced from Eocene. At

present, the only sign of Mount Sabalan activity is

various sulfuric and hot water springs indicating

post-volcanism phenomenon.  At the base of the highest

peak of Sabalan, a small lake exits.

Mount Sahand

It includes 12 cones separated from each other for a

couple of kilometers.  Sahand’s height is 3600m and

located in southeastern of Tabriz.  Its vast cone is

made of tuff and ash.  Existence of high volume of ash

and pumice pieces in far distances indicates vigorous

explosion of this mount.  This phenomenon has probably

had an effect on the burial of mammals of around

Maraqeh (Darvishzadeh).  The compostion Sahand lava

has been rhyolitic, dacitic and andestic.  The

activity of this volcano has been started from early

Quaternary, and today it is in relative calmness

period.

آشنایی

فعالیت آتشفشان سهند

محیط رسوبی گدازه‌های سهند

چینه شناسی آتشفشان سهند

ویژگی تکتونیکی آتشفشان سهند

سنگ شناسی آتشفشان سهند

آثار زیست محیطی آتشفشان سهند

تحولات ماگمایی آتشفشان سهند

• در سهند تغییر و تحولات ماگمایی در طول زمان صورت گرفته و این تحولات ناشی از تفریق ماگمای اصلی بر اثر نیروی گرانش می‌باشد. به گونه‌ای که ، در محفظه ماگمایی ، از ماده مذاب اولیه با ترکیب آندزیتی ( آندزیت قرمز گل ) ، سنگهای اسیدی شامل داسیت و ریوداسیت بوجود آمده است.
  
  
• با توجه به ترکیب شیمیایی سنگها ، به نظر می‌رسد که ماگمای تشکیل دهنده سنگها از ذوب بخش پوسته زیرین حاصل شده است.
  
  
• با توجه به نتایج زمین گاه شماری ، مراکز آتشفشانی سهند از اواسط دوره میوسن تا اواخر پلیتوسن ، بطور متناوب فعال بوده است.

مباحث مرتبط با عنوان

• آتشفشان
• آتشفشان تفتان
• آتشفشان چینه‌ای
• آتشفشان دماوند
• آتشفشان سبلان
• رسوبات آذر آواری
• گدازه آتشفشانی
• ماگما
• مواد آتشفشانی

List of tunnels by length

• The Seikan Tunnel in Japan is the longest rail tunnel in the world at 53.9 km (33.4 miles), of which 23.3 km (14.5 miles) is under the sea.
• The Channel Tunnel between France and England under the English Channel is the second-longest, with a total length of 50 km (31 miles), of which 39 km (24 miles) is under the sea.
• The Lærdal Tunnel in Norway from Lærdal to Aurland is the world's longest road tunnel, intended for cars and similar vehicles, at 24.5 km (15.2 miles).
• The St. Gotthard Tunnel from Göschenen to Airolo in Switzerland, opened on September 5, 1980, is the world's second longest highway tunnel at 16.32 km (10.14 miles).
• The Ryfast road program in Stavanger, Norway includes the tunnel Solbakktunnelen, which is scheduled to be opened within 2015. This tunnel will be 14 km long, making it both the world's longest underwater road tunnel and longest underwater highway tunnel. The tunnel will have four driving lanes in total, and a speed limit of 90 km/h.
• The Hsuehshan Tunnel in northern Taiwan opened on June 16, 2006 with a length of 12.955 km (8.05 miles). This tunnel is the longest highway tunnel in Asia and the 4th in the world (in 2006).
• The Rennsteig Tunnel in middle Germany runs under the Thuringian Forest over a length of 8.5 km (5 1/5 miles) and is currently Germany's longest tunnel. The highway A71 connects Erfurt with Schweinfurt.
• The North Cape Tunnel in northern Norway, connecting the island of Magerøya with the mainland, was the world's longest undersea road tunnel when opened in 1999, at about 7 km. It reaches a depth of 212 m below sea level.
• Päijänne-tunneli is the world's longest complete tunnel that is bored into cliff. It is located in southern Finland and it is 120 km long. Its purpose is to provide the Greater Helsinki metropolitan area with fresh water.

   Coal is mined to burn in power plants to make electricity. This electricity lets us live a lot easier. Often the coal is not buried very deep and it is quite easy to strip the soil and other material off to get at the coal. During mining, the mine companies have to save the soil that is stripped off and replace it after the coal has been mined. This protects the productivity of the land. Many specialists such as engineers, soil, plant and water specialists, and equipment operators are all involved in the land reclamation team.

A. In front of the strip mine, soil surveyors will map the types of soils and say which topsoil and subsoil should be saved. They measure the depths of soil materials and examine their chemical and physical properties. The land reclamation specialists then tell the equipment operators how deep they should scrape off the soil and where to take it. These operators then remove the soil and place it immediately on reclaimed land or pile it up for later use.
B. The largest piece of equipment in a strip mine is called the "drag line". It is like a crane with a huge bucket at the end of the cables. The drag line removes all the material on top of the coal so the coal can be mined. It piles up all this material (called "spoil") on the side of the mine where the coal has been removed. We cannot see the coal loaders and trucks in this picture because they are just out of sight in the large gap where the drag line cables are. The trucks get in and out of the mine on a ramp cut down into the mine at one end. The trucks take the coal to the power plant.
C. The first job after the mining is done is to level the spoil piles. They are not pushed out flat as a pancake. Some small hills and slopes are left so the land is like it was before the mine. Rain water and snow water run off easier if there is some slope to the land. This makes it easier to farm. After the spoil material is levelled, topsoil taken from the pre-mine side is moved over by truck or scraper and placed on top. Sometimes a bulldozer smooths the topsoil to make sure it is the same thickness all over. Then the soil is cultivated and seeded. The first crop is usually a hay crop.
D. Over the years hay crops are rotated with grain but hay is the main crop because hay plants such as alfalfa and grasses help build healthy soil. Lakes and ponds are planned for when the bulldozers push down the spoil piles. Shrubs and trees are planted for wildlife habitat. The landscape after mining is much like it was before; a mixture of sloping land with crops, meadows, bush and ponds.

Nature of the Work

These workers are responsible for operating various pieces of machinery and equipment for blasting, construction, exploration, extraction, and research at mining and drilling sites. Workers sometimes operate specialized mechanical or electronic equipment, tools or instruments to collect data.

Miners are employed by mining companies and specialized contractors in mine construction, shaft sinking and tunneling. Well drillers and servicers are employed by service contractors, petroleum producing companies, oil companies and well-logging or testing companies.

Main Duties

Both of these groups of workers spend most of their day performing physical duties. Working conditions can sometimes be difficult and hazardous.

Underground miners operate drilling machines to produce designated blasting holes, test geological formations or produce underground passageways. Their activities also include working with explosives, operating load-haul-dump (LHD) machines, and maintaining mining machinery. These workers may also be required to install air and water pipes, scale loose rock, and construct timber supports and cribbing.

Oil and gas well drillers and well servicers direct rig crews in setting up for exploration, and operate controls for drilling and hoisting machinery. Their activities include operating recorders and computers to collect data, maintaining operation records, and some data interpretation. In some cases, workers drive well service or wireline trucks to and from well sites. Most of the oil and gas activity in B.C. is in the northeast part of the province.

Example Titles

• underground miners:
• blaster - underground mining
• chute blaster
• diamond driller - underground mining
• drift miner
• driller
• faceman/woman, coal mine
• jumbo drill operator
• miner
• mining machine operator
• mucking machine operator
• raise miner
• scooptram operator
• oil and gas well drillers & well servicers:
• assistant driller
• directional drilling operator
• downhole tool operator
• drill stem tester
• driller
• electric line operator
• logging and perforating operator
• service rig operator
• slickline operator
• wireline operator
• well testing operator

Education and Training

Workers in this occupational group must be at least 18 years old with a minimum of Grade 10. Grade 12 is preferred by most employers.

Underground mining occupations are generally considered to be skilled fields. The equipment and techniques used are varied and complex, with many areas requiring significant safety and skills training. There is, however, no specific post secondary education required for employment in these occupations, and training is usually provided on-the-job. An ability to work in an underground environment is one of the most important requirements.

Training for hardrock miners is on-the-job or in a simulated setting. Length of training depends on the complexity of the skills required and the company. Several years of experience is generally expected for more senior and higher-paying jobs, or for employment with development crews.

To become a blaster within the mining industry in B.C., a permanent blasting certificate issued by the Ministry of Employment and Investment is required. (An incidental certificate can also be issued, primarily for safety fuse detonation.) Prospective blasters must be at least 18 years of age, and must work as an assistant under the supervision of a certified blaster for a period of three months to a year. A written examination must be passed and an inspector must be satisfied that the applicant is qualified to perform the duties. Preparation for this exam includes both on-the-job training and study of theory about explosives and blasting, which is supplied in study guides compiled by the Ministry of Employment and Investment. An applicant is allowed to write the exam upon recommendation of a mining company. Blasting certificates issued by other organizations, such as the Workers' Compensation Board, are helpful in understanding the theory of explosives.

Employment as a surface (rock and soil) mining driller usually requires three months to two years of on-the-job training and related experience. Many companies prefer that a driller work for at least a year as a miner to become familiar with mining techniques.

High school graduation is usually the minimum education necessary for rotary well-drilling and related occupations. Between five to ten years of the on-the-job training and experience in other positions on the drill crew are normally required before becoming a rotary driller.

A two-year Mining Program at the British Columbia Institute of Technology (BCIT) covers all aspects of the industry, including preparation for diamond drilling and blasting (although it does not confer a blasting certificate).

BCIT also offers a two-year Petroleum and Natural Gas program. This program is designed to cover all aspects of the petroleum industry. Admission requires Grade 12, with algebra 12 and physics 11 or chemistry 11.

Generally, these workers require some mechanical ability, basic analytical skills, and good communication skills. Basic knowledge of computerized systems may be required. Independence, adaptability, and an ability to effectively respond to problems and emergencies is necessary. An ability to follow precise instructions, obey safety regulations, and work as a member of a team are essential. In addition, blasters must have good hearing, eyesight and manual dexterity, and be emotionally stable. Drillers also require manual dexterity, and a capacity to stoop and crouch in order to set up drilling equipment. Rotary well drillers need enough strength to push heavy piping, and must be able to work in awkward positions. Often, these workers must be able to adapt to unpleasant atmospheric conditions.

Working Conditions

Underground mining occurs in a unique work environment. It requires work in dark and damp conditions with varying temperatures. Those employed in this group may also work alone, in small areas, with little supervision or communication.

Oil and gas work takes place outdoors and workers are vulnerable to all kinds of weather. Workers should be prepared to spend their days at a noisy and dusty or muddy work site. In addition, workers may also have to move from location to location in the search for oil. Working conditions are sometimes difficult. All workers are required to follow strict safety codes and must wear gloves, eye protection, hard hats and steel-toed boots.

Although workers spend most of their day performing physical duties, this is a job that demands mental alertness as well. Mistakes can be very costly and dangerous. Workers must be able to come together as a team to ensure the safety of all crew members.

Rotating shift work is usual. A typical shift may vary from 8 to 12 hours depending on the worker's position and the location of the work. Workers often belong to unions, where seniority may be important in obtaining shifts. In the case of smaller operators, work may be on a contract-to-contract basis and layoffs may occur in between.

The estimated average earnings for all B.C. workers in this group were $44,500 in 1994. Workers employed full time, full year earned an annual average of $51,700. Both figures are above the provincial averages ($28,700 and $39,800, respectively), reflecting in part the higher compensation for challenging working conditions. Underground miners have slightly higher average wages than do oil and gas well drillers. However, industry sources suggest the above earnings are too low for underground miners and that they can earn between $50,000 and $85,000 for full-time, full-year work.

This is a small occupational group. Employment decreased from 1,650 in 1990 to 1,450 in 1995. The majority of these workers (86%) are underground miners. Due to the nature of the work, self-employment is almost non-existent at 2%, which is well below the provincial average (11%).

At 3%, part-time work is well below the provincial all-occupation average of 22%. This may be due to the fact that some operations are kept running 24 hours a day and workers usually work an entire 8 or 12 hour shift. In some cases the work site is remote and may require travel and/or camp accommodation, a situation which does not easily allow for part-time workers.

The unemployment rate for this group is about double the provincial average. This reflects the seasonal nature of work in the oil and gas sector as well as the slower than historic operating levels in the mining industry. This group is also vulnerable to changes in business cycles. Fluctuating commodity prices and varying patterns in metal consumption can affect employment levels drastically.

Workers in this group are mainly employed in metal mining (37%) and services related to mining (26%). There is a small representation in non-metal mining (8%), crude petroleum and gas drilling (8%) and coal mining (6%).

Most of these workers are located in the rural areas of the Okanagan/Kootenay (45%), which is a traditional mining area in B.C. The rest are mainly located in Northern B.C. (22%), and on Vancouver Island (17%).

There are very few women (3%) in this occupation.

A higher than average share of workers are in the 25 to 44 age range (61%). This reflects the physical demands of the job. Workers under the age of 25 account for only 9% of this occupational group, which is lower than the B.C. all-occupation average. This suggests that few of these occupations are entry-level positions and that many workers probably start as general labourers and then move into these groups after they have gained other related on-the-job training.

Employment Prospects

Employment in this small occupational group is forecast to grow much faster than the average for all occupations through to the year 2005. A total of 630 openings is projected, including growth and replacement jobs, for the years between 1995 and 2005. Of the 630 openings, 400 are forecast to come from the mining industry. Most of the openings will result from new openings created by expected new mining developments.

Mining industry sources state that they do not expect as big an increase in employment as is given by this forecast. They expect that the opening of new mines in some areas of B.C. will be offset by mine closures elsewhere. Currently, there are surplus workers in the southern part of the province while there are opportunities in the north. This situation is expected to continue.

Skill requirements are changing within this group. Employees need higher education levels and a broader range of skills. New mining methods as well as the development and adoption of new technology will result in a demand for more highly skilled workers in this occupational group. Technological changes have led to higher production levels with fewer workers.

General ups and downs in the economy can drastically affect employment demand for this occupational group. There is a direct relationship between economic activity and mineral consumption and economic growth usually has an impact on the demand and prices for minerals. Fluctuating commodity prices and varying patterns in metal consumption affect employment levels by making properties profitable or unprofitable. Industry analysts suggest that the oil and gas industry is affected by changes in the business cycle, but generally less so than mining.

Government incentives are in place in the mineral industry to promote exploration in areas with high mineral potential. According to industry sources, government deregulation, which allows foreign companies to explore and extract minerals in B.C., has led to a very competitive industry for mining and oil and gas companies.

Mobility for workers between companies and industries is somewhat limited by differences in production technologies. In addition, many companies follow a policy of promotion from within whenever possible. For underground miners and oil and gas drillers progression to crew supervisors and managers is possible with experience or a combination of experience and education.

Related Occupations

• machinery and transportation equipment mechanics (731)
• driller and blasters - surface mining, quarrying and construction (7372)
• motor vehicle and transit drivers (741)
• heavy equipment operators (742)
• supervisors, mining and oil and gas (822)
• mine service workers and operators in oil and gas drilling (841)
• primary production labourers (861)
• central control and process operators in manufacturing and processing (923)

Trends and Projections