Deep-seawater Oceanographic Survey:

An Experience in Facing Challenges and Opportunities

Sholihin

1,a

, Mukhtasor

1,b

, Abdullah Ammar

2,c

, Sony Junianto

1,d

, Muchammad Iqbal Havis

3,e

Ocean Engineering Department, Institut Teknologi Sepuluh Nopember, Indonesia

PT Permata Tera Daya, Surabaya, East Java, Indonesia

PT ITS Kemitraan, Surabaya, East Java, Indonesia

abdoellahammar@gmail.com,

sony09@mhs.oe.its.ac.id,

muchammadiqbalhavis@ymail.com

Keywords: ADP/ADCP Method, Deep-Sea Survey, Survey Challenges, Survey Opportunities.

Abstract: Onshore and offshore structure planning requires wave and current data which are the result of direct

measurements on site. One area that affects the measurements is the deep-sea, where the area has large wave

energy and currents that greatly affect the condition of the waters adjacent to the location of planned coastal

and offshore structures. One of the most widely used survey equipment is ADP or ADCP. This paper explains

the experiences of collecting oceanography data in deep-sea. The survey method entails placing an equipment

on the seabed, which will emit signals indicating the flow and wave data according to the desired time and

depth. The survey process, especially for the deep-sea, requires good preparation so as not to fail. The result

of this paper is the identification of the technical, natural and social challenges of such project. The technical

challenges are tool stability, buoyancy effects, and visualization tools with underwater camera system,

underwater visibility, and sedimentation. Natural challenges are big waves, strong currents, and weather. The

social challenges are destruction of property, fishing grounds on land, and the behaviour of local people.

Therefore, before the survey, safety procedures and documents must be made in the form of HIRA (Hazard

Identification and Risk Analysis). The authors hope that the challenges identified in this survey can be

considered for other surveyors conducting similar projects in mitigating potential failures during the survey.

1 INTRODUCTION

The vast oceans of Indonesia have a huge potential to

meet the wide range of human needs. Indonesia's

maritime potential takes shape in various forms such

as ocean currents, tidal waves, and others. Sea current

is the water mass movement towards equilibrium

which causes horizontal and vertical displacement of

water masses. The movement is the result of several

acting forces and factors that influence it.

An ocean current is the mass movement of sea

water from one place to another, either vertically

(upward motion) or horizontally (sideways

movement).

According to Gross and Gross (1996), a current

may be caused by wind movement, movement of

thermohaline, tide flow, turbulence, tsunami, and

another wave. Another potential for wave source is

the tidal wave. These environmental conditions may

be used to classify a potential site, for example to

mark a potential location for a tidal wave-basd power

plant (Junianto et al., 2020).

According to Xie et al. (2019), tidal wave is a

phenomenon in which sea water rises and falls

periodically caused by a combination of Earth’s

gravity and the gravitational pull of astronomical

objects, primarily the Sun, Earth and moon. The

influence of other celestial bodies is negligible due to

greater or lesser distances. Under such circumstances,

ocean waves play a very big role in the potential TSB.

Research on waves and ocean currents has been

widely implemented in Indonesia to determine its

potential. Oceanographic surveys mostly use

Acoustic Doppler Current Profiler (ADCP)

(Sindlinger et al., 2005; Guerrero et al., 2014;

Bouferrouk et al., 2016; Latosinski et al., 2017;

Huang, 2018; Santos et al., 2020; Scherelis et al.,

2020; Yin et al., 2020). The equipment is mostly

placed under a vessel to measure ocean current

conditions, for example at a depth of 35.94 to 50.94

Sholihin, ., Mukhtasor, ., Ammar, A., Junianto, S. and Havis, M.

Deep-seawater Oceanographic Survey: An Experience in Facing Challenges and Opportunities.

DOI: 10.5220/0010855900003261

In Proceedings of the 4th International Conference on Marine Technology (senta 2019) - Transforming Maritime Technology for Fair and Sustainable Development in the Era of Industrial

Revolution 4.0, pages 173-177

ISBN: 978-989-758-557-9; ISSN: 2795-4579

173

m, obtaining an average speed of 40.51 cm/ sec with

a south westerly direction.

ADCP is one of the main tools used to determine

the value of the speed and direction of ocean currents

of a body of water. Its use is already very helpful for

human needs in various depths. Oceanographic

surveys are rarely carried out in the deep-sea, so

information on constraints and opportunities is rarely

found in references. Considering the remarkable

potentials of deep-sea waters, this paper will thus be

discussing:

1. The identification of challenges of deep-sea

oceanographic marine survey in Indonesia.

2. The opportunity to develop deep-sea surveys.

2 POTENTIALS OF DEEP- SEA

SURVEY

Deep-sea has biological and physical characters of

not letting sunlight penetrate through after a certain

depth. This condition forces the ecosystem in there to

adapt to it as well as to different physical condition in

general environment. By having several

characteristics, such as low temperature, stable, clear,

not pathogenic, containing nutrients, minerals such as

magnesium (Mg), calcium (Ca), potassium (K) as

well as other minerals in large quantities, deep-sea

holds a great potential for exploration.

Usage of Deep-sea Water (DSW) is not limited

only to matters relating to fisheries, but also for other

things such as industrial purposes, and even health

and environmental rehabilitation (Shane, 2015). The

potentials of the deep-sea comes from very rich

chemical contents and excellent physical conditions.

In a hydro-oceanographic survey work, there are

various activities performed as bathymetry survey

(mapping the shape of the seabed), measurements of

ocean currents, ocean tidal measurement,

measurement control nets (benchmarking), sampling

of seawater and seabed sediments, and others. Hydro-

Oceanographic surveys usually done in vary of jobs

in coastal areas or offshore. Due to the varying

parameters of deep-sea measurements, various tools

have to be employed to collect these data. Required

tools include:

1. Bathymetry: Single Beam Echo Sounder (SBES)

or Multi Beam Echo Sounder (MBES),

2. Ocean currents: Current Meter (CM) or Acoustic

Doppler Current Profiler (ADCP),

3. Tides: palm of tidal / Tide Staff or Tide Gauge,

and

4. Ocean waves: Automatic Water Level Recorder

(AWLR) or Wave Recorder, etc.

In deep-sea surveys, one of the main types used

are ADP NORTEK AWAC 400 kHz (Figure 1).

AWAC withstands water pressure up to a depth of

100 m, has an accuracy capability of up to 1.5 Hz

pulse wave, and is able to measure current speed and

direction. The specifications are explained in Table 1.

A survey in East Java began from a depth of 35 m

below the sea surface. With the depth of at least 35m,

we classify the challenges of deep-sea survey using a

case study in eastern Java's survey into several parts.

Figure 1: Nortek AWAC 400 KHz.

Table 1. Technical specifications of NORTEK AWAC -

400 kHz.

Water velocit

measurements

Maximum

rofilin

100

ran

Cell size 1.0-8.0

Number of cells

ical 20-40,

max. 128

Velocity range

±10 m/s

horizontal, ±5 m/s alon

Accuracy

±1% of measure

value ±0.5 cm/s

Maximum out

ut rate 1 Hz

Internal sampling rate 2 Hz

Wave measurement o

tion (AST)

Maximum depth 100

Data types

Pressure, one

velocit

alon

each

eam, AST

Sampling

(output) rate

Velocity

0.75 Hz

AST

1.5 Hz

No. of sam

les

er burst 512, 1024 o

2048

senta 2019 - The International Conference on Marine Technology (SENTA)

174

2.1 Technical Obstacles

Deep-sea marine survey is strongly influenced by the

uncertain natural conditions. Therefore, preparation

and monitoring are important to obtain a good

measurement output. Some technical barriers are

caused by stability of the ship, which may allow for

less measuring equipment to be installed onboard to

maintain its stability.

Figure 2: 30 GT Vessel is suitable for deep-sea survey.

3 CHALLENGES OF DEEP- SEA

SURVEY

Deep-sea water surveys introduce more challenges

than shallow water surveys. Waves are the main

factor taken into account because it will introduce

forces against coastal structures. The calculation of

the planned structure takes into account wave

classification according to the relative depth, which is

the ratio between the water depth d and the

wavelength L so that it becomes



𝑑

𝐿





. The ocean

wave is formulated in Equation (1) as follows:

𝐿

𝑑



(1)

Where:

d : depth

L : wave period

Figure 3: web frame of ADP construction.

In the case of East Java study, the survey vessel

used was a vessel of about 30 GT (Figure 2). The ship

was originally a fishing vessel equipped with a pulley,

which was used to roll the rope to lift up the

instruments. The instruments on the ship were not

stable because the wave height exceeded 2 meters.

Therefore, the ADP instrument had to be framed to

stabilize it when it was lowered to a water depth of

150 m. ADP web frame (Figure 3) was useful to

provide additional weight effect and increased

stability to maintain the position of ADP on sea floor

against external forces.

Another technical obstacle of using ADCP for

deep-sea water survey was the poor underwater

visibility beginning at 150 m depth. Ideally, the use

of ROV would be preferred to monitor the equipment.

However, the cost of deploying an ROV is very

expensive. Instead of using ROV, monitoring was

carried out using a MK-I deep-sea Underwater

Camera System (Figure 4) to monitor ADP at a depth

of 150m. MK-I had a much lower operational cost

compared to the ROV.

Figure 4: Visualization of MK I Deep-Sea Underwate

Camera System.

3.1 Nature Challenge

The seabed had a calmer condition than the surface.

However, predictions of current speed and direction

(Figure 5) in the bottom area were a challenge that

must be handled at the time of the survey.

Deep-seawater Oceanographic Survey: An Experience in Facing Challenges and Opportunities

175

Figure 5: Current velocity and direction prediction at 100m

at the time of ADP monitoring (Junianto et al., 2020).

The challenges did not include only current speed

and direction, but also the water temperature.

Therefore, it was necessary to ensure various safety

requirements were met for this survey.

3.2 Social Challenges

The deep-survey was done in the offshore area far

from the coastal area. Despite the remoteness of the

location, vandalism still occurred. The deployed

survey equipment was not attended and therefore was

lost because of sabotage. (Figure 6). This highlights

the need for surveys to have good security. The

marker buoy should not be put on the water surface.

The society around the oceanographic survey site

always determines the purpose of the survey activity.

They ensure no losses on equipment occur to the

surrounding site. Therefore, it is important to

approach local societies before the survey.

Figure 6: Sabotaged Buoy of ADCP.

Figure 7: Fishing Net Disturbing The Buoy of ADCP.

In addition, the survey marker buoy was caught in

fishing nets in the sea (Figure 7). This can interfere

with the data retrieval process by ADCP. The

placement of equipment at the survey location should

also consider the fishermen's activities around that

location.

4 DISCUSSIONS

The safety of personnel and equipment is paramount to

the sustainability of the survey. In order to prevent risk

to personnel and instruments, hazard and risk

identification is necessary. This process is necessary to

anticipate the risks that may hinder the activities of the

survey. Table 2 shows a list identifying hazards that

could potentially occur in the survey.

The explanation of activity during the survey in

the deep-sea area in previous section shows that the

risk of this survey is relatively large. Therefore, these

risks cannot be ignored during the planning stage for

deep-sea surveys. The reports during this survey,

especially in the technical and social aspects, can then

be used for future surveys.

Health and safety (K3) as a whole means that all

workers involved in a field project are entitled to

health and safety services regardless of the status of

sector (formal/informal), company size, and type of

work. Both the development and growth of the

industrial sector are always accompanied by a huge

problem of workplace accidents and occupational

diseases (Scherelis et al., 2020).

5 CONCLUSION

A successful deep-sea survey can be performed after

considering several aspects. These aspects include

senta 2019 - The International Conference on Marine Technology (SENTA)

176

environmental, technical and social factors. This

paper has presented activity in every aspect during a

deep-sea survey. The paper may serve as a reference

in the future to mitigate potential risks in carrying out

deep-sea surveys.

Deep-sea surveys may have more complex

environmental conditions, especially in sea level

conditions where breaking waves do not occur. The

survey equipment must be more advanced and tested

for its strength so that data security, safety and quality

are guaranteed. Another concern in this activity is the

social interactions which may cause deployed

equipment to be stolen or damaged.

REFERENCES

Bambang Triatmodjo, 1999. Teknik Pantai, Beta Offset,

Yogyakarta (in Bahasa).

Bouferrouk, A., Saulnier, J.B., Smith, S.H., Johanning, L.,

2016. Field measurement of surface waves using a 5-

beam ADCP. Ocean Engineering, 112, 173-184.

Gross, M. and Gross, E., 1996. Oceanography - A View of

Earth 7th Edition. Upper Saddle River, New Jersey:

Prentice Hall.

Guerrero, M., Tuther, N., Archetti, R., 2014. Comparison

under controlled conditions between multi-frequency

ADCPs and LISST-SL for investigating suspended

sand in rivers. Flow Measurement and Instrumentation,

37, 73-82.

Huang, H., 2018. A modified Simpson model for estimating

random uncertainty of moving-boat ADCP streamflow

measurements. Flow Measurement and

Instrumentation, 61, 84-93.

Junianto, S., Mukhtasor, Prastianto, R.W., Wardhana, W.,

2020. Motion responses analysis for tidal current

energy platform: Quad-spar and Catamaran types.

China Ocean Engineering, 5, 677-687.

Latosinski, F.G., Szupiany, R.N., Guerrero, M., Amsler,

M.L., Vionnet, C., 2017. The ADCP’s bottom track

capability for bedload prediction: Evidence on method

reliability from sandy river applications. Flow

Measurement and Instrumentation, 54, 124-135.

Santos, A.I., Oliveira, A., Carinhas, D., Pinto, J.P., Nuno,

Z., Freitas, M.C., 2020. The acoustic properties of in-

situ measured suspended sediments and their

implications on concurrent ADCP response- Case

studies of the Portuguese inner shelf. Marine Geology,

419, 106079.

Scherelis, C., Penesis, I., Hemer, M.A., Cossu, R., Wright,

J.T., 2020. Dataset for concurrent echosounder and

ADCP measurements at a tidal energy candidates site

in Australia. Data in Brief, 31, 105873.

Sindlinger, L.R., Biggs, D.C., DiMarco, S.F., 2005.

Temporal and spatial variability of ADCP backscatter

on a continental slope. Continental Shelf Research, 25,

259-275.

Xie, C., Li, M., Wang, H., Dong., 2019. A survey on visual

analysis of ocean data. Visual Informatics, 3, 113-128.

Yin, Y., Liu, Z., Hu, P., Hou, Y., Lu, J., He, Y, 2020. Impact

of mesoscale eddies on the southwestward counter

current northeast of Taiwan revealed by ADCP

mooring observations. Continental Shelf Research,

195, 1040.

Table 2. Hazard Identification and Risk Analysis.

No Hazard Risk Miti

ation

Mobilization/Demobilization

Instruments

stolen

Instruments

lost

 Attaching keys and

securit

cove

 Guarding during

travel

Instruments

shaken

Broken

instruments

Packing with safety

tool box and selecting

a suitable vehicle

Instruments Deployment

Over-

capacity

oat

The boat

sinks

Using qualified boat

Broken rope

while

installing

instrument

Instruments

lost

 Usin

certified ro

 Hiring qualifie

winch operator

Flipped

Bad

measured

data

Using

allast and

anchor, develop stable

frame, deploy in weak

current period, visual

check with underwater

camera

Data Recording

Insufficient

power

Bad/lost

measured

data

Use new battery

2 Vandalis

Buoy/

marker lost

Monitoring

periodically, using

sling wire attached on

buoy, and 24-hour

uardin

3 Hit by other

object

Instruments

flipped

 24-hou

uardin

 Two 24 hour stan

uardin

oat

Data Acquisition

Broken rope

when lifting

the

instrument

Instrument

lost

Using certified rope,

and hiring qualified

winch operator

Download

failure

Incomplete

data

Using require

attery

set, using high grade

data cable, and avoid

hard impact

Social Issues

Vandalism

and

deliberate

damaging

Equipment

removed

from survey

site

Approaching local

leader and local

people around the

survey site, and

submitting notification

and permit to the

Marines, Headman

and DKP

Deep-seawater Oceanographic Survey: An Experience in Facing Challenges and Opportunities

177