Indonesia Conference Directory

Corresponding Author
Bagus Endar Bachtiar Nurhandoko

Institutions
1 Physics Department, Institut Teknologi Bandung, Jalan Ganesha 10 Bandung, Indonesia;
2 Rock Fluid Imaging Lab, Bandung, Indonesia
3 Telkom University

Abstract
Pore pressure prediction methods have been developed by several researchers who only use well log data as a basis for determining the relation between velocity and pore pressure. Pore pressure prediction by using laboratory measurements to get the relation with velocity is still rarely conducted. In this paper, the prediction of pore pressure is done in multi-stages or sequentially involving the results of rock physics laboratory measurements for each reservoir lithology (carbonate, basement, and sand) and combining them with field measurement data for each well using statistical rock physics and statistical neural network methods. This method involves all measurement data from the core in the laboratory, well data, including data: lithology, measurement of pressure data in well (RFT, DST, etc.), hydrostatic trend, acoustic and elastic log data, porosity, and mud weight information. The whole data are trained using statistical neural network. Then, the knowledges are used to predict the pore pressure by considering lithofasies of log and also seismic lithology.

Keywords
Statistial Neural Network, Pore Pressure, Seismic Rock Physics

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/m6XMVNfWRwKq

Corresponding Author
Rosliani Widia Pamungkas Isburhan

Institutions
a) Master Program of Geophysical Engineering, Institut Teknologi Bandung
b) Global Geophysics Group, Institut Teknologi Bandung
c) Research School of Earth Sciences, The Australian National University

Abstract
Palu City is a city on the island of Sulawesi with very complex geology. There are many active faults on Sulawesi Island, one of which is the Palu-Koro Fault system which extends NNW-SSE direction. Thick sediment under Palu City can cause amplification of the soil during an earthquake so that the damage will be quite severe. In order to characterize the subsurface structure of the City of Palu, microtremor data processing was carried out from 22 stations using the Horizontal-to-Vertical Spectral Ratio (HVSR) method. HVSR is a method for obtaining subsurface information from a single station measurement that can be used to examine seismic risk. HVSR is measured by comparing the Fourier spectrum of horizontal components with vertical components. The amplitude of this ratio, H/V curve, is varying with frequency. The H/V curve containing amplification information and the related dominant frequency which can then be inversted to obtain subsurface information, such as S-wave velocity and layer thickness. In this study, the inversion was carried out by using the PSO (Particle Swarm Optimization) algorithm. The PSO algorithm is stochastic optimization technique inspired by social behavior of bird flocking when searching a promising area for food. In order to evaluate the consistence of obtained results we also compare with the model from OpenHVSR program. The obtained shear velocity model shows that low velocity zone (less than 700 m/s) related to the sediment layer is around 200 m with a relatively small misfit at around 1.3.

Keywords
HVSR; S-wave Inversion; Monte-Carlo Algorithm; PSO

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/cm4g8wHQCaL9

Corresponding Author
Bagus Endar Bachtiar Nurhandoko

Institutions
1 Physics Department, Institut Teknologi Bandung, Jalan Ganesha 10 Bandung, Indonesia;
2 Rock Fluid Imaging Lab, Bandung, Indonesia

Abstract
Cap-rock integrity as well as reservoir integrity assessments have become a key element in the design and operation of steam injection projects and a critical element in the selection of a maximum steam injection operating pressure. The applicability of steam injection requires good knowledge of reservoir and geomechanic aspects. In addition, injecting steam into a very shallow unconsolidated reservoir has potential risk of having loss of containment issue. By necessity, these cap-rock integrity assessments involve geomechanical engineering principles and have generally lead to more use of reservoir-geomechanical simulations (one way coupled or sequentially coupled) in the establishment of what is termed “safe” maximum steam injection pressures. In this method, geomechanical parameter (stress state model (overburden, hydrostatic and pore pressure), elastic model (Young Modulus, Shear Modulus, Poisson including failure criteria i.e. Mohr-Coulomb), and rock’s reservoir properties (lithology, porosity, permeability, water saturation etc.) are required as input data. The methods will integrate the whole data with coupled reservoir properties and geomechanics modeling to calculate changes of rock strength due to steam injection. These cap-rock assessments have included geological framework studies of caprock, insitu stress determination, reservoir and cap-rock property characterization, failure criteria from numerous situations and numerical simulations to ensure the steam injection scenario always in proper condition. Alternative injection scenarios are suggested to be performed in risk area, as follows: (a) Steam injection and production are performed simultaneously; (b) steam injection, heating and production are performed simultaneously; (c) heating, production and injection are performed sequentially.

Keywords
Geomechanics, Caprock Integrity, Time dependend Temperature-Chemical Alteration, Rock Physics

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/eC27Xzjw8FPy

Corresponding Author
Asep Rohiman

Institutions
Center for Geological Survey, Geological Agency, Ministry of Energy and Mineral Resources. Republic of Indonesia
Jl. Diponegoro No. 57 Bandung 40122, Indonesia

*The corresponding author’s e-mail address : asep.rohiman[at]esdm.go.id

Abstract
Fossil fuels are the main fuel that is still used by the community. Along with the increasing population of Indonesia, the need for oil and gas fuel is also increasing. Therefore, oil and gas exploration activities are needed to obtain new economical reserves. A regional surface soil gas survey consisting of 300 sites were placed on approximately 1 km intervals using existing rivers, streams and navigable waterways within the onshore portion of the Boka area located in Mimika Regency in Papua for evaluation of the hydrocarbon potential. This soil gas data contains very large magnitude anomalies consisting of a unique mix of light hydrocarbons (methane, ethane and propane) and carbon dioxide. Generally very large concentrations of methane and CO2. In this case, these two gases (methane and CO2) have a clear association with the larger petrogenic ethane and propane gases. In addition these coherent anomalies occur at sites where the ethane/propane ratio exhibits somewhat noisy ratios with some sites having ratios less than one, a condition that is generally found only within macro gas and oil seepage environments where both volatilization and degradation can randomly alter their ratios. The logical conclusion is these biogenic gas anomalies associated with noisy ethane/propane ratios are evidence of a macro seepage environment. In spite of the very regional spacing (1 km) the largest magnitude anomalies clearly suggest two main clusters of anomalies. One occurs on and along strike with the Aiduna fault zone, and the second clusters along the coast line near the mouth of the Aiduna and Umari rivers. These anomalies suggest deep source oil potential exists over the entire area surveyed. The Aiduna River traverse crosses the northern trace of the inferred Aiduna fault with more impressive anomalies, including the largest magnitude propane and C2+ gases found, following fairly close to the Aiduna fault trace. These oily soil gas anomalies confirm the existence of a wide-spread and active subsurface petroleum system. Given adequate density, it appears that future soil gas surveys could provide a cost effective approach to focusing on and defining areas which could be further developed before much more expensive exploration tools (seismic) and drilling are employed. An offshore sampling survey might confirm and extend these coastal anomalies into the adjacent offshore.

Keywords
microseepage, geochemistry, mimika, oil and gas, gas chromatography

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/ZkNcxX4QWReu

Corresponding Author
Reny Reny

Institutions
Modeling and Inversion Laboratory,
Physics of Earth and Complex Systems,
Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology,
Jalan Ganesha Street number 10 Bandung, Indonesia, 40132

Abstract
The distribution of the volcanoes in indonesia gives positive impacts in the form of fertile land where many residents live to grow crops. Besides having positive impacts, there are also negative impacts in the form of natural disasters. Improvement in mitigation of natural disasters is needed to avoid any form of harm and undesired losses. Information on the accuracy of earthquake parameters is an important part of natural disaster mitigation efforts. Hypocenter relocation of earthquakes is a step to improve the accuracy of earthquake parameter information. The relocation of hypocenters earthquake is performed using the Coupled Velocity-Hypocenter method. The research area is Gede volcano which is included as type A active volcanoes. The data were processed using GAD and VELEST 3.3 software resulted in epicenters that were spread around Gede and Pangrango volcanoes. The hypocentre were distributed between -2.5 ‒ 5.2 km depths based on GAD calculated. After relocation using VELEST 3.3, they were distributed between 1.0 ‒ 10.5 km depth. The calculated. The calculated magnitudes of volcanic earthquakes occurred in December 2017 vary between 0.6 to 2.7. the difference between the initial and final velocity models is small. After station correction step, the velocity profiles beneath the most of station is indicated as sedimentary layers, and beneath of the peak station, it is indicated as instrusive rocks.

Keywords
Volcano, hypocenter, epicenter, method, GAD, correction, station, and Coupled Velocity-Hypocenter

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/jBhRFybmcgw7

Corresponding Author
Fakhri Rahadian Budi

Institutions
ITB

Abstract
Seismic method has been used as a non-destructive alternative in geotechnical testing. Through this test, several geotechnical parameters can be determined, while mantaining low costs, time and environmental impact. However, seismic wave sensors that are commonly used (geophone), are usually expensive and heavy. Since 2004, there have been several research that develop and prove the capabilities of MEMS accelerometers as cheaper and lighter seismic wave sensors. This study aims to develop a seismic wave sensor based on the MEMS ADXL335 accelerometer, calibrate its frequency response, and determine the field performance of the seismic wave sensor. The frequency response calibration is done in the range of 10-100 Hz, and will be presented as a plot of sensitivity to frequency. A subwoofer was used to simulate sinusoidal movement on a tested accelerometer with a controlled frequency, and on a 10 Hz traditional geophone as a reference. Geophone’s maximum signal gives maximum velocity of the sinusoidal movement, thus by utilizing simple harmonic oscillation equation, maximum acceleration of sinusoidal movement (and later MEMS accelerometer’s sensitivity) could be acquired. High resolution oscilloscope was used on to record MEMS accelerometer and reference geophone output signal during frequency response test. Field test was done using three identical accelerometers with ±40 cm spacing, using sledgehammer to generate seismic wave and 16-bit seismograph to record detected ground vibration. Frequency response calibration shows relatively constant responses 10 – 100 range (±3 dB tolerance towards static sensitivity), proving MEMS accelerometer’s wide bandwidth and superiority in measuring low frequency vibrations. Field test shows accelerometer’s ability to smoothly integrate with a seismograph and detect surface wave in field setting.

Keywords
ADXL335, Calibration, Capacitive MEMS Accelerometer, Field test, Frequency response, Seismic sensors

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/FpkYJVx7fwBv

Corresponding Author
Adam Sukma Putra

Institutions
(a)Department of Physics, Universitas Gadjah Mada
Bulaksumur, Special Region of Yogyakarta, 55281 Indonesia
*adamsukmaputra[at]ugm.ac.id
(b)Department of Physics, Bandung Institute of Technology
Jalan Ganesha 10, Bandung 40132, Indonesia

Abstract
Multichannel seismic reflection data processing of line 250 at the Coast of Southern California has been done by using Echos®. The purpose of this research is to separate multiple reflections from the primary reflection. Multiple reflections yield dramatic effect especially on marine seismic survey. Multiple reflections in marine seismic data is the noise caused by waves that trapped in a layer of sea water or rock layers. One of geophysics exploration problem is removing multiple reflections from primary reflection. Multiple reflections often destructively interfere with the primary reflection making interpretation difficult, so it’s needed to get seismic section free from multiple reflections. There are some methods to attenuate the multiple reflections, one of them is Hyperbolic Radon transform. Hyperbolic Radon transform method works by transforming the data from time-offset domain into the Radon domain. Primary reflection and multiple reflections can be separated into Radon domain. In the end of this research, seismic section before and after multiple attenuation using hyperbolic Radon transform were compared. Based on the result of processing, it can be concluded that hyperbolic Radon transform is effective to attenuate multiple reflections at 0,24-1,25s TWT. But, it can eliminate some of data and makes seismic section seen unclear.

Keywords
Multiple; Radon Transformation; Seismic Processing; Marine seismic; California Coast

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/feRMwvjEDpJ8

Corresponding Author
Ennita Riana

Institutions
a) Department of Earth Sciences, Faculty of Earth Sciences and Technology, Bandung Institute of Technology, Jalan Ganesha 10, Bandung 40132, Indonesia
*ennitariana[at]students.itb.ac.id
b) Geophysical Engineering, Faculty of Mining and Petroleum Engineering, Bandung Institute of Technology, Jalan Ganesha 10, Bandung 40132, Indonesia
c) Department of Physics, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Banda Aceh 23111, Indonesia

Abstract
The Sumatran Fault stretches for 1,900 km, The 1900 km long dextral slip fault, the Great Sumatran Fault (GSF), accommodates a significant amount of the trench-parallel component of the oblique convergence between the Indo-Australian and Eurasian plates. The Sumatran fault, unlike other great transcurrent faults, is highly segmented. The largest irregularity in GSF is observed in the central part of GSF (around the equator) where the fault splits into two sub-parallel strands up to 35 km apart; named it equatorial bifurcation and is a region that has a high level of seismicity. This research was conducted with the aim to obtain the profile of the shear wave velocity (Vs) based on the results of the Rayleigh wave dispersion curve inversion. In general, the research are divided into four main stages; standard data processing, cross correlation and stacking, initial velocity model analysis, dispersion curve analysis, and direct inversion. Empirical Green’s Function is obtained from the cross correlation results of each pair of stations from the temporary seismic network around the location. The preliminary results show that based on the analysis of the EGF dispersive signal’s seismicity of the station pair oriented relatively northwest – southeast and northeast - southwest, obtained the dominant distribution of noise sources related to oceanic activity on the coast of the Indian ocean, in the 5 – 20 s range. In that periods range, the average group velocity varies from 2-4 km/s. The apparent anomaly is thought to be due to the bifurcation in the region.

Keywords
Ambient Noise Tomography; North Sumatra; Velocity Analysis;

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/dLDnCbJN8xfh

Corresponding Author
Shindy Rosalia

Institutions
(a) Graduate Program of Geophysical Engineering, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung
*shindy.rosalia31[at]gmail.com
(b) Global Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, Indonesia.
(c) Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia.

Abstract
Three-dimensional seismic velocity structure of crustal and upper mantle in West Java was reconstructed using the combination of body-wave and ambient noise tomography. We use P and S wave arrival data from nearly 1000 events to obtain a deeper (> 10 km), more regional velocity model and use ambient noise cross-correlation data from 75 temporal stations to obtain shallow (<10 km) velocity model with a higher resolution. The combination of both methods could give a comprehensive subsurface image of West Java, especially in the shallower part of northern West Java where there is a lack of body-wave raypath coverage. The seismic velocity structure obtained in this study could be very useful for understanding tectonic activity in the study area, which is important for earthquake disaster mitigation efforts in West Java. The three-dimensional seismic velocity could also be used as the input parameter of another seismological study, e.g. hypocenter determination.

Keywords
Body-wave tomography; Ambient noise tomography; West Java

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/yPMYBXnJTEct

Corresponding Author
Bagus Endar Bachtiar Nurhandoko

Institutions
1 Physics Department, Institut Teknologi Bandung, Jalan Ganesha 10 Bandung, Indonesia;
2 Rock Fluid Imaging Lab, Bandung, Indonesia
3 Physics Department, University of Mataram, Indonesia

Abstract
The vibration produced by an earthquake can cause liquefaction. Liquefaction events in the wells are influenced by the nature of soil, geological environmental and earthquake characteristics, as well as other factors such as rock grain size, groundwater level and ground vibration acceleration. There were a number of cases after the Lombok earthquake which were indicative of the occurrence of liquefaction, especially those observed at the location of residents water wells. After earthquakes, we found many phenomena of dry water wells, the occurrence of siltation of wells, broken pipes in deep drill wells, and the collapse of the walls of wells. Generally the surface soil layer in Lombok is loose sand, and as is known that the loose sand layer has a higher potential for the occurrence of liquefaction due to its grain characteristics. This paper presents sand grain size analysis of wells in North and West of Lombok which undergo liquefaction when 2018 Lombok Earthquake. The result show the distribution from shieve analysis, microscope sampling results, and also distribution from laser particle size analysis. This study is essential for the further analysis to the resistance of wells to vibration of erthquakes.

Keywords
liquefaction, earthquake, particle size analysis

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/rZxwWbuAqCJ8

Corresponding Author
Alhada Farduwin

Institutions
1. Master Program of Geophysical Engineering, Institut Teknologi Bandung
2. Global Geophysics Group, Institut Teknologi Bandung

Abstract
Ridge regression particle swarm optimization (RR-PSO) is an optimization technique based on the simulation of social behavior of some animal swarm that has been sucessfully used in many different engineering fields. In this study, RR-PSO was used to invert Rayleigh wave phase velocity curves that extracted from ambient seismic noise records to obtain the shear velocity (Vs) profile. The optimization algorithm is relatively faster, stable and the important aspect is that can provide uncertainty information of the inversion results. In order to determine the capabilities of the RR-PSO algorithm, the synthetic simulation was carried out using both noise-free and noise-contaminated data. The validity test includes the calculation of similarity index and estimation of the model uncertainty using their standard deviation. Based on the resulted model, the convergence of RR-PSO algorithm is relatively faster, stable and adaptable to some level of noise and can provide good model estimation of the subsurface. The application of RR-PSO to the real dispersion curve data is carried out in order to determine the seismic crustal structure beneath Nusa Tenggara islands.

Keywords
RR-PSO, shear velocity, Rayleigh waves, Nusa Tenggara

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/nJNKcxYwXDjr

Corresponding Author
Ardhi Rofi Mufdhila

Institutions
ITB

Abstract
Hydraulic fracturing has become an important method to increase the productivity of the well. Hydraulic fracturing will occur if the rock in the formation is given a tensile stress magnitude higher than the rock’s tensile strength. The insitu stress around the wellbore is unlikely to be tensile but some stress condition around the wellbore could lead to hydraulic fracturing given a pressurized fluid in the wellbore. We consider a two and three dimensional wellbore and assumed to be linear elastic and isotropic. Calculation and vizualiation of stress distribution around a wellbore has been done using finite element method. The model is applied by a minimum horizontal, maximum horizontal, overburden stress and the wellbore pressure. The wellbore pressure and the wellbore direction condition is variated. Some of the wellbore pressure data is derived from fracturing theory like Terzaghi, Daneshy, and least principal stress criterion. The data about the tensile strength of the rock around a wellbore is needed to predict wether the fracture will occur or not. The result show that there will be some minimum wellbore pressure and stress region that could lead into tensile failure that could lead to hydraulic fracturing. We also observed that the stress distribution in the horizontal well could predict wether the fracture will be transversal or longitudinal.

Keywords
Hydraulic Fracturing, Stress Distribution, Finite Element, Fracture Criterion, Well Direction

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/faB9K7ugPdNQ

Corresponding Author
Bagus Endar Bachtiar Nurhandoko

Institutions
1 Physics Department, Institut Teknologi Bandung, Jalan Ganesha 10 Bandung, Indonesia;
2 Rock Fluid Imaging Lab, Bandung, Indonesia
3 Physics Department, University of Mataram, Indonesia

Abstract
The series of Lombok earthquake started from July 2018 followed by two mainshocks and thousands aftershocks caused massively damage to the public facilities and residential areas. As a result of the earthquake measuring 6.9 SR, most of the wells were also damaged due to liquefaction. The most devastated areas usually have several units of lithology, namely: coastal sediment alluvium and pyroclastic rock. This research was conducted to characterize subsurface geological condition including groundwater aquifers using 2D resistivity tomography. Series measurements of 2D resistivity tomography at the some impacted area of 2018 Lombok Earthquake can reveal the relationship among the most of devastated area, the subsurface geological condition, the vibration, and also the most impacted liquifaction area. The most of impacted areas caused by 2018 Earthquakes lie on the very loose sand and shallow aquifer zone. The resistivity tomography, however, shows that in the North Lombok area usually has high resistivity thin layer (with a range of> 500 Ohm.m) around a depth of 10 m. This high resistivity layer is carbonate reef layer which may play a role as barrier of soil liquifaction especially when the earthquake’s wave vibrates the soil.

Keywords
Resistivity tomography, Lombok Earthquake, Liquifaction

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/DzutkReG7Mgp

Corresponding Author
Dieno Diba

Institutions
Physics Department, Bandung Institute of Technology, Bandung, Indonesia

Abstract
Papandayan Volcano is an active volcano located near Garut Regency, West Java, Indonesia. Magnetotelluric (MT) data acquisition was carried out in the Crater Mas area in 2009 with a total of 13 measurement points. This data acquisition was performed using a remote reference method to obtain better data quality by reducing measurement noise. The geomagnetic data acquisition was carried out in January 2019 in the crater area using a set of G-856AX Memory MagTM Proton Precision Magnetometer (PPM) with a total of 259 points. The result of MT modeling shows that the structure could be divided horizontally into two layers, namely the conductive layer at a depth up to 1km and the resistive layer at a depth of more than 1km from the surface. Conductive layer located near the surface may be interpreted as the presence of water or clay mineral. The two-dimensional forward modeling of geomagnetic result shows that the rocks with relatively low susceptibility values below the surface causes the anomaly at a depth of 30 to 100 meters. The low susceptibility values of the rocks might have been caused by thermal demagnetization due to high temperatures.

Keywords
Geomagnetic, Magnetotelluric, Resistivity, Papandayan Volcano, Susceptibility

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/F9EYywdVGpCz

Corresponding Author
Gunawan Handayani

Institutions
1,2 Laboratory of Earth Physics Bandung Institute of Technology

Abstract
The electrical complex impedance is very important physical parameter to determine the fluid and matrix condition of the rock sample. One mechanism in the samples that influences this complex, frequency – dependent behavior of resistivity is the disseminated metal ores which can block the pores and subsequently trigger the mechanism for storage/delay. Pore water ions build up on either side of the grain, results in the effect of a capacitor. This paper presents a simple experimental set up to measure the complex resistivity of rock samples. The main mechanism is generation of high voltage sinusoidal signal. This is implemented as collector voltage of a transistor. The high voltage sinusoidal signal then is applied on either side of the rock sample. At two distances of the sample we measure the resulting voltage using the oscilloscope. The observed delay can be considered as the measured phase, whereas the amplitude of the observed voltage is considered as the voltage. We determine the absolute impedance as the voltage divided by the current. Using this simple method we measured the complex impedances of 14 rock samples obtained from Halmahera Island. From the results of measurement, we tried to infer and to model the disseminated metal ores of the samples.

Keywords
Complex Impedance, Rock Samples Measurement

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/XZCNHtMLxbKY

Corresponding Author
Agus Laesanpura

Institutions
Institut Teknologi Bandung
Jl. Ganesha 10 Bandung, 40132

Abstract
Lok Ulo area is a main river extended from north to South of Kebumen area. This area is famous for basement of pre-tertiary rock exposed to the surface. The evidence of fault by geology directly is difficult due to in part by thick weathering surface, and second it could be hid beneath the river. The gravity instrument of micro Gal precision is running to overcome the problem across the area where anticline valley is very subtle. The geology reconstruction is doing but the geophysics evidence is giving another solution. The anomalous of 2.5 mGal is resulting from 1.5 km downthrown block. The reconciliation finally deducted hence the fault is separating two block. Afterwards, by consequence the thickness of sedimentary rock is separating into two block, the west part and east part separating each other by fault. The vertical throw of fault show significant separating the mélange complex from the others. It is estimated from gravity data that the fault take deep seated origin. The thickness tertiary sedimentary of claystone cover the mélange (the older one) and separating each other. By consequence, the east part is thicker than the west

Keywords
Gravity, fault, Pra-tertiary

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/fKhHFr7ZkBEt

Corresponding Author
Kamila Permata

Institutions
Astronomy Department, Bandung Institute of Technology, Jalan Ganesha 10, Bandung 40132, Indonesia
kamilapermata13[at]gmail.com

Abstract
Sunspots are darker, cooler areas on the surface of the sun and have strong magnetic field. The morphology of the sunspots group is classified into seven types based on the Zurich classification. The Zurich classification was modified and expanded to improve the objectivity of the definition of sunspot classification. The modified classification is called McIntosh classification that has other parameters to classified sunspot such as size, stability, and complexity. Sunspot has proper motion - the result of the interaction between solar rotation, magnetic field, and convection. In this study, we measured the coordinates of 304 sunspots umbra as tracer in the rising phase of the solar cycle 24th to obtain the relation of sunspots umbras velocity to Zurich and McIntosh classification. Coordinates of sunspots were measured using AIA images at a wavelength of 4500 Å from SDO (Solar Dynamic Observatory) with JHelioviewer software. From the measurement, we got that for the penumbral class in McIntosh classification, x class (no penumbra) and r class (incomplete penumbra) has the largest latitudinal and longitudinal velocity. For the sunspot distribution in McIntosh classification, i class (intermediate) and c class (compact) has highest latitudinal and longitudinal velocity.

Keywords
Sunspots; Proper motion of sunspots; Zurich and McIntosh classification

Topic
Earth and Planetary Sciences

Link: https://ifory.id/abstract/ZpkeUButbEK2